[Mac350]

Hi, Just acquired this 2004 bike that has done 100 odd miles a year for the last 10 years. Got it home running better with the choke on I think due to the perished inlet rubbers. Will order new rubbers and clean out the carb, just wondering if these bits are that bad what else should I definitely look at before riding? Tempting as it is to do a full service, I'm salivating over the service manual, but the summer is only going to last so long so i'd rather do some ride now and get stuck in later. But I don't want to risk damage by neglecting something that has been neglected too long already. 

Its got a free flowing exhaust and a BS29 carb (have i worked it out right its from the 500 and this 350 would have a BS26 as standard?), I can see it makes sense to change both. Previous owner said his previous owner said something about installing different cams but not sure which. It goes well enough to filter through cars and get safely ahead of everything from the lights making it very usable. Coming home along some little hilly lanes I could leave it in 3rd gear most of the time and use the torque which is what I pictured doing with this bike but the unclean road surface makes me wish it had a decent back brake, it has no feel to it, I'll take that apart sooner rather than later but are there any particularly good shoes to recommend or tips for improving it?

On these AVL engines generally is the chat about them not thumping like a CI over stating things? I rode an Enfield in India in the 90s and as soon as I got on this I felt like I was back there. I'm not seeing the love for these online like I'd expect. It feels like this is the sweet spot in Enfields for UK use. It feels so much like a classic bike, kick start only, headlight direct off engine, everything is accessible to work on, can run without a battery but no points to worry about and has a front disk which in UK traffic feels like a very worthwhile concession. Left hand gear shift and five gears also. It really feels classic and special but is entirely usable. I'm surprised they aren't more sought after.

[Mac350]

Is it right I can't edit posts? I just realised it looks like I'm saying i'm going to change the carb and exhaust, instead I meant i can see why it made sense to do it when one was changed already they did both. It seems a good combo, not sure top speed yet but on a fast B road I wasn't feeling like I should have waited for a 500 and I wanted as light a bike as possible.

I've a die grinder waiting to work on the ports if I take the head off at some point. I feel like I'm going to enjoy getting to know this bike like none before, just begging to be tinkered with somehow   

[Raymond]

Hi Mac, welcome to the forum. You can edit posts - after you've, uhm, posted, there should be a Modify button at top right. Cheers, Raymond

[tooseevee]

Is it right I can't edit posts? I just realised it looks like I'm saying i'm going to change the carb and exhaust, instead I meant i can see why it made sense to do it when one was changed already they did both. It seems a good combo, not sure top speed yet but on a fast B road I wasn't feeling like I should have waited for a 500 and I wanted as light a bike as possible.

I've a die grinder waiting to work on the ports if I take the head off at some point. I feel like I'm going to enjoy getting to know this bike like none before, just begging to be tinkered with somehow   

      There is a certain time after posting that you can go back & edit your post. After that you can't.

         Good luck with your 350. Sounds like you lucked out on finding a really nice oldy but goody. The AVL is really nice once you fix all the bad little things that were "installed" right at the factory in those days.

        2004 was the year I started looking for an Enfield. Found my brand new, leftover 2008 Classic at an out of business dealership in 2010. It has a similar mileage history to yours & many, many hours of mods & tweaking.

       Again - good luck & keep posting. The AVL section is a desert.

[Adrian II]

Welcome to AVL Land.

I cut my RE teeth on the 500 Electra-X. Being 500s, their engine components are more highly stressed than your 350, which should have an easier time of it.

The whole thumping thing seems to be an Indian obsession, trying to get them to tick over like vintage stationary engines, fine if you like Ruston Hornsby semi-diesels, not too good on a bike, where lugging the engine in too high a gear to get The Thump doesn't do the big ends any good. I'm assuming if it's the 2004 model it will have the 5-speed gearbox (correct me if I'm wrong), just use it! What size gearbox sprocket is fitted, 16T?

The very early A350s came with Dell'Orto PHBH28 carburettors are by all accounts were quite lively by 350 Bullet standards (I happen to have a spare one of these carbs!). Interestingly the factory fitted 29mm CV carbs to the UCE 350 Bullets after these replaced the 350 AVL models, the final examples of which were on 24mm CV carbs.

As for tuning the 500 AVL engines, a set of Redditch "S" cams is the thing if you're doing all the other tuning mods, so these might do the job on a 350 AVL, possibly the P.O. has already fitted some. If you can't get them, standard Indian Bullet cams are close, but watch the inlet valve head to piston crown clearance.

Weak spots in the Electra-X were flaky big end pins on early ones, fragile cam followers and the electric start sprag clutch being prone to fail, not a worry if yours is K/S. These can all be sorted.

The back brake, if you have a 5-speed bike, can be improved by converting the gear shift to the right foot and putting the brake pedal on the left where it belongs, the cross-over shaft arrangement with the right-foot brake is a bit spongy.

If you need spares, try here: https://www.pricepartmotorcycles.co.uk/

Hope this helps,

A.

[Mac350]

Thanks for the replies. I've ordered the parts I definitely need so hopefully will be up and running by the weekend and will take it from there. The tires are looking a bit old, not quite plastic feeling yet but I will put new ones on before autumn assuming all else is well. Any thoughts on ENSIGN ROAD UNIVERSAL front and back? I can only find talk of the trials version which looks a bit more than i'll need but a lot of the lanes I'm going down are dirt up the middle so something with a tread would help

Seems like Machismo owning is a little trickier for parts being all grey imports. According to the combined retired model parts catalogue page 173 the BS29 carb was for the 500 which is good probably but it wasn't what Hitchcock's were expecting and they don't seem to be using the catalogue I found. Weird how the AVL era seems to be a dark age.

Now you say it, the thumping was a thing I noticed those years ago with accelerating was satisfying from very low revs. It was a long time ago but it felt similar on this bike, like you say I'll just ride it. Yes 5 speed, not seen what gear on the front yet.

I have to hope if PO changed cams they are redditch ones then, if/when I get in there do you know how are they identifiable?

I remember many years ago a friend having read Zen and the art of motorcycle maintenance buying a classic bike and spending all weekend taking it apart and putting it back together again. I spent the weekend riding instead. Only now do I get it. I don't know what it is but where as my old inline 4 begged me to redline it, this thing begs me to get some spanners out. The smell is inviting for a start, and the grime is somehow friendly on the hands, just washes off. The difference between having to remove a load of plastic covers and being able to just squat down at its all there is immense. I think i'm understanding the draw to steam engines now as well, you can see it all working on the outside, obviously more than this bike but at least I can see where the bits are and make sense of it.

[Paul W]

I’m sure you’ll soon get to love it. My bike is half similar to yours in that it has the Electra crank case set up but with the traditional iron barrelled engine (and left side rear braking with a twin leading shoe front, rather than a disc). I bought it as a bad weather bike, so I didn’t have to clean my big Honda 750 every time I rode it. The Bullet has done 23,000 miles since, the CB750 only 2,000!

[AzCal Retred]

"I'm surprised they aren't more sought after."

These were "swan-song" machines. Roller crank, better head design, gear drive oil pumps, 5-speed & disc brake. All the mods an Iron Barrel rider might want on a pre-unit construction engine.

Practically they are great, aesthetically they don't quite fit the mold of a 1930's-1940's era machine for most people looking to "go back" - mostly the same folks spending $$$ to add on many of the mods you already have. 

Aesthetics don't pay the rent, but all of it is a cheaper hobby than going to the bar. Great find!

[Mac350]

It did occur to me if this 2004 bike is giving me great classic bike goodness, what if I went back much further... not planning anything but it just occurred to me. I think I'm going to be happy with this for a good while though. It has enough stop and go that I can hoon it around town a bit, and it has cruise through the country lanes in steady style. If I had a garage where i could keep some really interesting old and rare beast maybe, but to have one bike to do it all this is probably perfect

[Adrian II]

Early AVLs were 4-speed, 2004 was probably the first season with the 5-speed box. Adjusted right, the latter is a little sweetie compared to the 4-speed Albion gearbox.

My tyre of choice is the Avon AM26, 3.25"x19 front and (most likely in your case) 100/90 x 19" on the back. Heidenau K34s might also suit.

Hitchcocks' sometimes struggle with parts for non-UK imports, but hang in there. The retired models parts book is an excellent idea, so going by the part number is probably your best bet. Henry Price is familiar with the Indian home marker models and always worth contacting for odd-ball stuff.

A quick way to tell if your AVL cams have been replaced by something more Bullet-y is to have the tappet cover off and check the tappet adjusters. If they're screwed almost right the way out, someone has fitted cams with a smaller base circle than the AVL cams! The picture below has a few different cams. the two columns in the middle are the "S" cams, the AVL cams are the two top right. The "S" cams helpfully have the letter"S" stamped on the inside of cam wheels, along with the letter "I" of "E", I'll let you guess what they stand for.



Good used sets come up on eBay every now and again, Hitchcocks' might also have some in their used parts section.

There may be something in the swansong model business, compared with the many years the 350 iron barrel was in production in India (not forgetting the UK 350 Bullet production from 1949 to 1961/2) , the AVLs managed about ten years in one form or another. The 350s worked well enough but were never official imports, sadly. The first 500 AVL was the Electra-X appearing in Europe and the USA late in 2004, great bikes once properly sorted, but their reputation was tarnished by poor quality crank pins on the early ones plus any number of sprag clutch failures. The final versions were the Indian market A500 Machismo and the US market AVL Classic.

Why don't these models get the love? Besides the poor mechanical reputation, they're not always seen as "proper" Bullets. The more aggressively-styled motor was not to everyone's taste, with the squared-off oil pump bodies drawing some flack, though if you go back far enough in RE history most models had this! I've heard them unfavorably compared to the compressors used on larger refrigerators. Also much of the engine is covered in ghastly sliver-grey powder coating which is probably quite tarnished by now. This can be removed by chemical stripping and vapour-blasting, then you can give the timing cover and gearbox end cover a good polish! Also the "cruiser" styling on Thunderbird model was very much to Indian tastes!

A small minority of RE enthusiasts do still have a soft spot for these models. I liked my Electra-X so much (until it went bang!) had a hybrid 500 AVL engine built in a set of bullet crankcases and put it in an English Royal Enfield frame.



A.

[Mac350]

The Bullet has done 23,000 miles since, the CB750 only 2,000!

Says it all doesn't it. About the qualities of the ride as opposed to efficiency getting places. Funnily enough I was just going to get a CB500 because you can get a decent one for £1000 and it would have been enough. I had the train ticket bought but in the morning I just wasn't feeling it. Called it off much to the annoyance of the seller and then this bullet had appeared overnight a few miles away from me on facebook. I'm still congratulating myself for trusting my gut 

[Mac350]

Thanks again for the useful info

Early AVLs were 4-speed, 2004 was probably the first season with the 5-speed box. Adjusted right, the latter is a little sweetie compared to the 4-speed Albion gearbox.

Seems like 2004 is the year then as by 2005 it wont run without a battery

but their reputation was tarnished by poor quality crank pins on the early ones

should i be safe from that with a 2004 engine? What are the symptoms to watch for?

Also much of the engine is covered in ghastly sliver-grey powder coating which is probably quite tarnished by now. This can be removed by chemical stripping and vapour-blasting, then you can give the timing cover and gearbox end cover a good polish! Also the "cruiser" styling on Thunderbird model was very much to Indian tastes!

I seem to be lucking out on that, the casings look great and it matches the muted green colour and the chrome is perfect still. Interesting really hadn't occurred to me but they reversed the shine from engine to the tank.



I'm really feeling liberated by the feeling that there is nothing wrong with modifying these bikes, i'm told even from the factory they can be quite varied depending what was in the parts bin that day

[Paul W]

Mine looks very different now to how it left India, but I’d like to think that everything I’ve changed looks like it might have been put there at the factory. It came with a four speed “fearbox” (that was a predictive text word failure, but very appropriate  ) but I bought a five speed, which has transformed the ride, bridging the big gap between third and fourth.

[Mac350]

Mine looks very different now to how it left India, but I’d like to think that everything I’ve changed looks like it might have been put there at the factory. It came with a four speed “fearbox” (that was a predictive text word failure, but very appropriate  ) but I bought a five speed, which has transformed the ride, bridging the big gap between third and fourth.

Ah so the 5th gear isn't much taller than the 4th on a 4 speed? I guess it makes sense we'd not get away with large gaps if we dont have the same low down grunt of the CI engines, though I was up and down some little twist hilly lanes and the AVL seems to have plenty low down to allow me to stay in 3rd most of the time. It makes that sort of riding lazy and fun while I was imaging on a revvy bike it would get annoying constantly changing gear or having to keep it at high revs. I feel like I should have a go on a CI at some point because its been that long I really can't remember to compare.

[Adrian II]

Fortunately this bike is a native 5-speeder! Both 4 and 5-speed boxes have a 1:1 ratio in top gear. Overall gearing is taller on an Indian 350 than the old Redditch 350s, you can swap gearbox sprockets to suit your needs. Can't work out why you want to stay in 3rd most of the time!

Seems like 2004 is the year then as by 2005 it wont run without a battery

So it's one of the last of the kick-start only versions with the CDI ignition. I do wonder why more models weren't fitted with that.

should i be safe from that with a 2004 engine? What are the symptoms to watch for?

Maybe! As I mentioned earlier the 350 top-end is putting less strain on the bottom end than the 500. If the big-end does fail, you will hear it, but you can always check the scavenge drain plug for debris. Good news is that the later UCE/EFI con-rod and big end kits are a direct replacement for the AVL and not horribly expensive, though you have other rebuild options when and if the time comes.

What you can do before anything goes south in that department is to fit a sump magnet to pick out any nasty little abrasive steel particles which the mesh on the scavenge drain plug might let through, these bits can score-up the scavenge pump housing. Drill and tap the plug 1/4" BSF, put a couple of 5mm neodymium button magnets on the end of a 1/4" x 1" BSF set screw (not stainless) and fit that into the plug.



Only some iron filings so far, but this one has an Alpha Bearings big-end...

I'm really feeling liberated by the feeling that there is nothing wrong with modifying these bikes

Keep the original bits safe, though! Did you have anything in mind?

A.

[Paul W]

I couldn’t help noticing that your newly acquired bike has a primary drive (left side) cover with a centre bolt fixing and therefore the ‘O’ ring seal. Mine, although it has the iron engine, has the later “AVL” Electra X type cover, with peripheral screws and a “paper” type gasket.

Question for Adrian: .
Is this an indication of the difference between CDI ignition and the TCI ignition that my 2004 bike has?

Seems that RE were playing “mix and match” in that year.

[Mac350]

Can't work out why you want to stay in 3rd most of the time!

I was just enjoying the low torque and marveling at the ability to do it with minimal changes. These Devon lanes are tiny, barely space to get past a car so I need to slow down for every blind corner, and its hilly. I'd be continually changing gear on another bike but this just chugged around them almost as if it was made for the job of tootling around English lanes some time in the distant past 

Good idea for placing the magnets there. If I don't have a BSF tap in the draw of many taps i'll have a UNF, i'm guessing not standard metric as too course to resist the vibrations? Or too French for an English bike 

I couldn't work out if the bike was fastened metric or imperial and then realised its both

Keep the original bits safe, though! Did you have anything in mind?

A.

having taken the air filter boxes and carb off I was wondering why not just leave them off and put a K&N filter on a carb, spotted the breather box removal to chain oiler tip for getting rid of that, I don't need much battery so perhaps fit something even smaller and lose that box. Trouble is it would need to cut mounts off to really look right which is a bit committed. It looks great as it is and doesn't need paint so I probably won't do anything yet, nothing I might regret anyway, until i've see a lot of others mods to consider. I did get the original bars with the bike but I really like the look and position of the ones on there now.

[Raymond]

Just to say I'm really enjoying this thread - the discussion here gives a good perspective across the various engine types, ignitions, primary drives and permutations shipped from the factory in the early years of the century. Sounds like Mac350 is well chuffed with his 350, as indeed I am with my 500 iron barrel.

Mind you, Paul W has me thinking about whether to swap in a right-change 5-speed box - investigate.

[Paul W]

Raymond, I wasn’t too happy with my bike as a four speeder. The 3rd-4th gap meant that I was forever cog swapping on many of the Peak District hills. Third was often too low, but the engine began to lose rpm as soon as I changed up to “top”.

The 500 should be better placed to pull top better. The 700 twin even better - they all used the same gearbox internals, only the drive sprocket was changed between the different bikes.

The ratios of the 5 speed work really well on my bike, being better spaced. It’s a lot of work to change the gearbox and expensive to obtain one, too. I was lucky, being offered one at far less than the usual going rate. Other owners recommend the Hitchcock’s CR gear set as an alternative.

[Mac350]

Sounds like Mac350 is well chuffed with his 350, as indeed I am with my 500 iron barrel.

Its the choice of type of bike that i'm most chuffed with so far. The journey is the destination, so needed an entertaining ride not an efficient A to B bike. but I started thinking it would be good to have a back up mode of transport for a once weekly 200 mile round trip for work and before you know it i'm thinking Honda, but sod it, I can just leave a bit earlier if i need to take the bike one day and hopefully I'll have the Enfield in a reliable state anyway. I overtook a classic BSA coming down the A303 today, he didn't look to be having a bad day.

[Adrian II]

I couldn’t help noticing that your newly acquired bike has a primary drive (left side) cover with a centre bolt fixing and therefore the ‘O’ ring seal. Mine, although it has the iron engine, has the later “AVL” Electra X type cover, with peripheral screws and a “paper” type gasket.

Question for Adrian: .
Is this an indication of the difference between CDI ignition and the TCI ignition that my 2004 bike has?

Seems that RE were playing “mix and match” in that year.

Answer: yes!

That's the same outer primary cover as used on the Sixty-5. Here's some piccies of the CDI alternator set-up, it's still loosely based on the old Lucas 6 coil alternators, but one coil is the CDI charging coil, the other 5 are divvied up between the AC headlamp supply and the feed to the reg/rectifier for battery, horn, stop and tail light and indicators. So on these the headlight AND the ignition are independent of the rest of the electrics.





This one has a pattern stator, the red and black pair of wires would be purple on a factory stator.

'm guessing not standard metric as too course to resist the vibrations? Or too French for an English bike 

1/4" gives better clearance for the 5mm magnets, UNF would do just as well in this case. Of course, if you have a M6.35 x 1.0mm tap handy... 

A.

[Mac350]

So on these the headlight AND the ignition are independent of the rest of the electrics.

I love the idea of this for some reason, though I've ended up with it purely by a fluke. Anything more complicated than this seems excessive now.

The horn is hilariously weedy sounding though. I looked at replacements available but without hearing it i've no idea. Is there a decent one you can recommend?

[Paul W]

So, as I thought, the CDI setup uses a  “conventional/traditional” alternator with the stator coils fixed on the inner chain case. The rotor runs inside the coil assembly.

The TCI (as you well know but others might not) has a completely different design where the stator assembly is located on the inside face of the primary drive outer case and the cup shaped rotor runs outside it. A pickup senses the passing of a metal reluctor “flag” welded to the outside face of the rotor and signals the TCI module to control the separate coil. The outer case needs to be very accurately located on the inner, to ensure that the stator is properly aligned inside the rotor. Hence it has locating dowels and fixing screws, rather than the less accurate single centre bolt.

The downside of the TCI is that it needs a battery to work. However, I believe that it will work down to 7 volts. On a kickstart only bike that’s not a problem and my bike came with a smaller battery (5aH) than the electric start AVL engined ones.

[El Saif]

It was a pleasant surprise when I bought a replacement battery for my kick start only RE Thunderbird AVL 350cc. The battery being only 5 AH was cheap.

My 2004 RE Thunderbird AVL 350cc also has a 5 speed gearbox which changes gears easily.

As I was raised on Japanese bikes, I also appreciate that the gear lever is on the left hand side.

[Paul W]

I converted my 5 speed to suit the existing layout of the bike with gear change on the right side.

[Adrian II]

I love the idea of this for some reason, though I've ended up with it purely by a fluke. Anything more complicated than this seems excessive now.

The horn is hilariously weedy sounding though. I looked at replacements available but without hearing it i've no idea. Is there a decent one you can recommend?

I ordered a cheap pair of China's finest last year from a UK supplier and fitted the high-tone one on my Redditch 350 Bullet, it seems absolutely fine. Hunt around, you might get the same set cheaper still.

https://www.ebay.co.uk/itm/235257738514

A.

[Mac350]

1/4" gives better clearance for the 5mm magnets, UNF would do just as well in this case. Of course, if you have a M6.35 x 1.0mm tap handy... 

A.

Happy days! My drawer of many taps provided as usual, a 1/4 BSF spiral flute no less so I can renew my excuse for not selling off my Herbert tapping head. And my drawer of infinite odd bolts provided a 1/4 x 1" BSF set screw. What I was thinking I might fail on was a 5.3mm drill bit but no, a Presto No.4 measures 5.3mm. I've got to a happy place where I very rarely have to go outside for anything    (other than chinese magnets)

[Mac350]

Only some iron filings so far, but this one has an Alpha Bearings big-end...

Are you saying they are good or not so good?

[Adrian II]

The iron filings are probably just normal bore wear.

The UK-made crank pins are considered to be better quality, though there's also a Jawa speedway crank pin the same size which can probably cope with a lot more than your engine can throw at it. Might be worth keeping in mind, assuming the oil holes line up. If Alpha Bearings re-condition an AVL crank with a failed big end they can not only fit a new decent crank pin, I have several cranks where they have also ground out the big-end eye of the con-rod and fitted a hardened steel inner sleeve (or outer race), which is about as good as an AVL crank could possibly get. Not cheap, though!

I have some of these 5mm magnets spare, send me your address in a private message and I'll post you a few.

A.

[Mac350]

I have some of these 5mm magnets spare, send me your address in a private message and I'll post you a few.

A.

Thats very good of you thanks but I already ordered some. I found some 5mm diameter and 10mm long which I think could be quite useful for other things

[Adrian II]

I think I'm using a couple of 4mm high magnets. You'll be able to see when it's all screwed into the scavenge plug if there's room for the oil to get past.

A.

[Mac350]

Jets wise the BS26 carb which was standard on a 350 has the same main 110 main jet anyway as a BS29 which was standard on the 500 and that is what I've found in mine.

Curiously though my pilot jet is 15 which would have been standard for the BS26 on the 350 while the BS29 on the 500 should have a 12.5. I'm assuming these are bigger for a higher number so wondering why it might as standard have a smaller pilot jet in the bigger carb for the bigger bore engine? And why I have the bigger jet for the bigger carb on the smaller bore... I just made sure it was all clean and put it back on so I will suck it and see when I get a minute to finish a bit of rewiring. The mixture screw was wound out 4 turns and the rubber before the air filter fully torn so plenty of reason for lean running as it was, to the point it was running right with the choke on all the way. I've wound it back to 2 turns out and will take it from there.

It was a bit of a faff getting the carb and boxes back on, there is clearly a best way to do this which I'd be glad to hear about from people here. What minimum do you remove to get the carb off and the order of things when putting it back on?

I noticed a loose cross head bolt on the throttle grip housing, left of the cable, that when i tried to tighten seemed like a stripped thread but then actually its just got a threadless bit of shank and a corresponding threadless part of the bore so once its wound in past the thread its neither tight or likely to fall out. Is this some deliberate thing thats more clever than it first appears?



There is a small plastic sliding cover on the front of this housing is that for spraying lube in? The plastic is so crappy feeling i thought i'd broken it at first when it moved but it seems like a sliding cover.

I dug out pictures of the Bullet i hired in Goa in 1992. Looking at the exhaust I can see why mine reminds me of it so much. I think I would have been disappointed with a standard UK spec exhaust.

[Mac350]

I changed the taillight from this useless thing



To this, which matches the stock mount nicely but now I need to get smaller indicators. Some chrome bullets? I'm very open to suggestions. I'll keep them next to the number plate for now.



It comes on a rubber mount which I had to use some of so it took a bit of fettling. Its all going a bit trials style, I have the stock handlebars but i like the one on it and due to my riding area i'll get some classic looking semi trials block tyres. But the exhaust will stay low. Hopefully it will look consistent enough



I put an LED bulb in which only just fit but is like a laser beam out the back, will probably dazzle drivers a little in rain but thats better than not being noticed.

[Adrian II]

Ebay has loads, bulb or LED, just find a set you can stand the look of and make sure the flasher unit is compatible if you choose LEDs. Oddly enough, when I went to add indicators to my Redditch 350, I deliberately chose the Indian pattern your Machismo has (apart from having orange lenses instead of clear), I reckoned they had a better chance of being seen.

A.

[Mac350]

I just went to add some grease to a clicking CV joint on my car and the transmission oil seal fell apart. No one has it in stock locally    I'm now faced with a 200 mile round trip on the not really ready for it bike

[Adrian II]

Whatever happened to "We haven't got any but we could get one here for tomorrow."? Could they not have one couriered in?

If course if the Machismo DOES do the round trip without any problems, it will help you to decide if it's a keeper!

Last thunk on the carburettor front, how about a 4-stroke Mikuni flat slide TM28 carb with accelerator pump?

A.

[Mac350]

Whatever happened to "We haven't got any but we could get one here for tomorrow."? Could they not have one couriered in?

If course if the Machismo DOES do the round trip without any problems, it will help you to decide if it's a keeper!

Last thunk on the carburettor front, how about a 4-stroke Mikuni flat slide TM28 carb with accelerator pump?

A.

I went out and attempted a long hill (there are a few between here and work) and it was flat out at 40mph. I pulled over to check temp of head and was 300 degrees F which isn't excessive by some numbers I've seen. There was a wee bit of white in the exhaust fumes... not there later when not pushing it could it be over rich making that?

Its not up for the trip so i've hired a car for a couple of days.

I took the breather pot off and found it full of mayo, the oil in the engine is clear so didn't panic, checked forum and have added Mr Prices one way valve to the order is that the best bet? I've not placed the order yet though so tell me more about the flat side and what does the accelerator do?

[tooseevee]

    Adrian will more & better to say, but put simply I'll give it a go.

      A regular slide operated carb does not shoot any gas into the intake when you twist the throttle. All you are doing is lifting (opening) the slide which increases air intake as the amount of gas being sucked out of the float bowl is increased as the needle rises with the rising slide. Twisting the throttle with the engine off squirts no fuel into the intake stream. All it does is raise the slide.

    Twisting the throttle quickly a few times does nothing as a pre-start technique.

    With an accelerator pump, you are actually squirting a shot of gas into the intake stream.

     My technique in the winter with an S&S was 2 quick throttle blips, 2 kicks with key off, then 1, sometimes 2 kicks with choke closed and it was running. Choke fully open in 20 or 30 seconds. No throttle blips in warm weather.

[Mac350]

    Adrian will more & better to say, but put simply I'll give it a go.

      A regular slide operated carb does not shoot any gas into the intake when you twist the throttle. All you are doing is lifting (opening) the slide which increases air intake as the amount of gas being sucked out of the float bowl is increased as the needle rises with the rising slide. Twisting the throttle with the engine off squirts no fuel into the intake stream. All it does is raise the slide.

    Twisting the throttle quickly a few times does nothing as a pre-start technique.

    With an accelerator pump, you are actually squirting a shot of gas into the intake stream.

     My technique in the winter with an S&S was 2 quick throttle blips, 2 kicks with key off, then 1, sometimes 2 kicks with choke closed and it was running. Choke fully open in 20 or 30 seconds. No throttle blips in warm weather.

Sounds like a complication compared to regular carb. What I should probably ask is which is easier for getting access to change the jets as I'll be doing that a fair bit for a while. I'm not trying to make this bike into a racing bike I just want it running right and normal performance. If the amal type does the job and looks good and is easy to fiddle with that probably the way to go. I'll have a classic old choke lever on the bars

A whole thread singing praises of the BS29 for an AVL 350. https://www.team-bhp.com/forum/motorbikes/165098-enfield-upgrade-bs26-bs29-carburetor.html Thinking about it mine was running better when the air hose was split almost in half so I'm wondering if the air filter is restrictive. It looks clean but maybe its the problem. It ran well, felt entirely normal and decently powerful with the split hose and the choke on. So maybe bigger main jet and less restrictive filter... I had already spoken to Allens and they pointed me to a PDF of mikuni jets and the one for the BS29 wasn't on there... I'm just thinking get a nice new amal type carb and cone now...

I am liking the fact that I'm learning the bike. If it was all plain sailing and just worked, I'd be in the dark when something happens out on the road at some point.

[Mac350]

Yeah I'll stick with the Wassell I think as I don't have 3 hands or twin push pull cables https://forum.classicmotorworks.com/index.php?topic=27427.msg322954#msg322954 

Good thing about the BS29 is its a doddle getting the throttle cable on and off. And the bike starts really easily hot or cold. Shame about the rest. I'll strip the carb again and try cleaning it more. Must be something I'm missing. What is the recommended detergent for a ultrasonic bath?

[Adrian II]

OK, ditch the air box and try a simple cone filter. I'd look and see if the needle could be raised a notch too. By the way, newer carbs with the enrichener cold start can be converted to cable operation for use with an old Amal-style choke lever on the handlebars, you just have to remember it works in the opposite direction.

I have the Mikuni TM36-31 pumper carb that I bought for my old 500 Electra-X, just 4 screws to undo to get the float bowl off for jet changing, I can't see the TM28 pumper being harder to work with. Again, the Dell'Orto PHF36s I currently use are easy enough to work on. The accelerator pump does what it says on the tin, it squirts a little extra fuel in to the carb when you open the throttle to prevent it running lean under acceleration, but as tooseevee says, it's handy for starting, too. Similar effect to tickling an Amal carb. The PHF32 was the carburettor of choice when Watsonian-Squire launched their go-slightly-faster kit for the Electra-X to replace the CV29, which, as I have said, was what RE India ended up fitting to the UCE 350. The smallest PHF is a 30mm, which probably wouldn't be excessive for the Machismo. The PHF range and the bigger brother PHMs were used a lot on the big Moto Guzzis and Ducatis.

I read some of the posts on that link from mostly 9 years ago, looks like - then at least - new CV 29 carbs could be had dirt cheap.

Shouldn't ordinary detergent work with an ultrasonic cleaner bath? It just needs to break the surface tension.

A.
A.

[tooseevee]

Sounds like a complication compared to regular carb.

      I don't think a carb with an accelerator pump is any harder to work with than one with a tickler or an actual choke or whatever. Many, many carbs have accelerator pumps. You just have learn what the various piece do and what order to tweak them, etc., & what the engine wants. The TM 32 is very simple to deal with once you understand what it wants. So are Amals I guess. So are S&Ss & Tillotsons & SUs & BS 29s. You just gotta work with them for a while.

     Sorry I screwed up that Reply #29 & left the Quote blank.

       

[tooseevee]

I had already spoken to Allens and they pointed me to a PDF of mikuni jets and the one for the BS29 wasn't on there...

     Anyone who specializes in jets will have jets for the BS 29. I had no trouble getting them from JetsRus. Adrian will be more help.

https://www.jetsrus.com/

    Or SUDCO

[Paul W]

  Thanks for the link to "Jetsrus"; I've bookmarked it. However, I've found of late that having parts posted from the States costs a lot; far more than it did only a few years ago.

[Mac350]

Ah hell https://forum.classicmotorworks.com/index.php?topic=36970.msg481500#msg481500

My other interest is boats. I see carb choice is to bike forums what anchor choice is to boat forums.

Consensus seems to be BS29 could work if you have to and if you are lucky, but if you can do, just get a better one. The main jet in mine is not the one on the jetsrus site, in fact i cant find if there for any carb so that might be a part of the problem. I'll take a photo when I'm back to it in a few days

I still haven't put the order in so am open to suggestions on which carb to buy. What is the most likely carb to work the best with my 350 AVL?

 

[Mac350]

Actually its a stupid question because they will all have pros and cons. To my (untrained) eye the Amal style looks the most right for the engine. There is also a lot of info online about tuning them and parts are readily available. Hopefully these are more intelligent questions:

Is there any carb that is so significantly easier to work on and tune that i should consider it instead?

Is there a carb that offers such significantly better performance that I should considering it instead?

[Adrian II]

Just remind me, what size inlet port is there on the cylinder head at the moment?

I think ALL the readily available aftermarket motorcycle carbs are easy enough to work on, if you have one with an accelerator pump there is not really that much more to it, access to main, pilot and needle jets is still OK. Certainly jets, slides and needles seem to be readily available for Amal/Wassell Mk1s, Dell'Ortos and Mikunis.

If price is your consideration you can get a Chinese clone of the Keihin PWK 28 carbs on Ali Express for £10, and big bags of jets for beer money, but most of them seem jetted for 2 strokes, so instead of being too lean in the mid-range they're way too rich. Needle jets and needle for 4-stroke applications DO exist for these carbs, but you'd have to track them down. JRC Engineering in the USA figured it out and had a range of PWKs set up for British bike use, and there was/is(?) a company called Brill Bike Parts in the UK selling them. Obviously getting one all set up for you costs a bit more. https://www.brillbikeparts.co.uk/products.html. Being adapted for British bike use these have 2" stud centre flanged bonded on.

The Mikuni seems to have registered as the quality option (needs a good external fuel filter), Allens' Peformance or Motocarb seem to know what they're doing, all the Mikunis I've tried seem to work out of the box with few adjustments needed. Probably has the edge on performance.

Dell'Orto is a well established make, you can HAVE my PHBH28 to play with (Enfield India's original choice for the model, remember!) and make a charitable donation if you think it's any good.

Wassells' clone of the Amal Mk1 appears to be a decent job, but if that's your fancy, go for the Evolution version which copies Amal's own upgrade for the Mk1 and addresses SOME of the Mk1 design's shortcomings.

A.

[Mac350]

Just remind me, what size inlet port is there on the cylinder head at the moment?

I'll check when I'm near it next and let you know.

I've ordered a compression tester as I'm seeing signs of leaking around the head gasket but I can't hear anything over the engine. I'm likely to take the head off before long anyway just out of curiosity so will order some gaskets. Its seeping a little engine oil from up that way as well but nothing a flick with a rag wont fix. I understand this is a common issue but not as bad as leaking from CI engines? I've watched some videos of people trying to make their Enfield 100% oil tight and it seems a bit over the top, but the head gasket leak could be an issue that should be sorted. It looks a lot like working on 2 strokes, not complicated looking like OHC engines. It would be good to check the exhaust and clean it out. I love the bit in the service manual where it says for this job "Take a potato..."  Wasn't expecting to see that

I think ALL the readily available aftermarket motorcycle carbs are easy enough to work on, if you have one with an accelerator pump there is not really that much more to it, access to main, pilot and needle jets is still OK. Certainly jets, slides and needles seem to be readily available for Amal/Wassell Mk1s, Dell'Ortos and Mikunis.

OK so no reason to go for non-wassell on the ease of fiddling score.

I suppose when trying to understand symptoms for tuning though, having the accelerator pump adds another variable i could probably do without adding.

If price is your consideration you can get a Chinese clone

Price is a bit of a factor of course but none of the carbs are that expensive and i'd rather pay for a reliable quality finished product. Normally I'm always buying everything second hand other than underpants, but at this stage I dont want the variable that the carb might have a wear and tear issue that I can't spot so I'll buy new or maybe highly trusted source used 

The Mikuni seems to have registered as the quality option (needs a good external fuel filter),

I took the petcock off the tank to check it and it had a little rust that got through the top screen but was stopped by the lower part, I can't even see the holes in the lower screen with a magnifying glass, so anything that gets through that can get through the jets presumably?

Allens' Peformance or Motocarb seem to know what they're doing, all the Mikunis I've tried seem to work out of the box with few adjustments needed. Probably has the edge on performance.

Allens didn't have info on the BS29 or any CV carb he said and the PDF of jets they pointed me to didn't have the one thats in the carb but its seeming like its not the original one which might be an issue anyway. I can't find a refurb kit. Can't find jets. Its an indian copy from a time where their manufacturing wasn't very quality, current Chinese copy probably better and I don't want that = just swap the damn carb for an established one. I'm going to give it one last clean out, put the needle clip to the middle, remove the air filter and give it a go then decide what to do.

Dell'Orto is a well established make, you can HAVE my PHBH28 to play with (Enfield India's original choice for the model, remember!) and make a charitable donation if you think it's any good.

Thats a damn fine offer thank you very much and I may well take you up on it. Would the throttle cable I'd need to get then anyway work for the Wassell if I decided to get that later? Do you know which one of these it is? https://www.dellorto.co.uk/product-category/dellorto-motorcycle-carburettors-parts/complete-carburettors-dellorto-motorcycle-carburettors-parts/phbh-26-to-30mm/

Playing is right, these machines are like living 3D puzzles with the prize of taking it for a ride if i overcome the challenges. I'm not at all feeling frustrated so far, anything that needs doing is just going to be a fun educational puzzle. I do all my own car repairs and have never felt quite this way about a car. That said I'm talking about the mechanical side short of engine repairs, removed turbos to clean them etc but not engine internals, whereas this bike engine seems like everything is possible which is maybe why its more enticing

Wassells' clone of the Amal Mk1 appears to be a decent job, but if that's your fancy, go for the Evolution version which copies Amal's own upgrade for the Mk1 and addresses SOME of the Mk1 design's shortcomings.

I wouldn't have a choice seems like the evolution is only one available now. But what are the MK1 shortcomings that haven't been addressed still??

[Mac350]

I'm coming full circle:

"Note: Lugging is when you open the throttle and the engine doesn’t respond with an increase in rpm. A
variable venturi carburetor relies on the incoming air’s velocity. The faster it passes through the venturi
the more lift (vacuum) it develops. The more vacuum (differential in pressure between the venturi and
atmospheric pressure) the more fuel will be drawn into the intake manifold. The difference in pressure is
the result of the piston drawing in the air/fuel mixture as it descends down the cylinder bore. The actions
of the carburetor and piston have a symbiotic relationship.
If the piston doesn’t pick up speed (increase rpm) as you open the throttle air velocity decreases. You are
letting in more air with less fuel being drawn into the venturi. The air/fuel mixture becomes very lean.
This dramaticaaly increases the chance you will suffer detonation, and or, catastrophic pre-ignition. Most
of you will have heard about the SU carburetor. This design prevents you from lugging the engine. It is of
a constant-depression design (often called Constant Velocity or CV)." https://vintagebikemagazine.com/technical-articles/amal/

The thing is my main riding area makes it very desirable to open the throttle when its a bit higher gear than it should be or i'll be constantly changing gear. The keeping it in 3rd I was on about before. I'll make a video at some point, its hard to imagine. How seriously should I take the worry though? Enough to stick with a CV carb?

But is there a better CV carb I should consider? Or an SU carb?? Looks even more right than an Amal...

[Mac350]

So its the down side of throttle responsiveness, if the engine doesn't keep up with the carbs responsiveness. I'm finding lots of search results for Harleys now using CV carbs. Makes sense because thats the sort of low revving riding people are expecting to do on a Harley, but they also want to blat away impressively sometimes, maybe especially inexperienced Harley riders. Which leads me to thinking is it still possible to pull from lower revs with any carb but I just have to wind it on slowly rather than whacking the throttle open like a newb. 

[tooseevee]

So its the down side of throttle responsiveness, if the engine doesn't keep up with the carbs responsiveness. I'm finding lots of search results for Harleys now using CV carbs. Makes sense because thats the sort of low revving riding people are expecting to do on a Harley, but they also want to blat away impressively sometimes, maybe especially inexperienced Harley riders. Which leads me to thinking is it still possible to pull from lower revs with any carb but I just have to wind it on slowly rather than whacking the throttle open like a newb. 

     harleys are more capable of doing that than long stroke, 500 or 350cc vertical singles.

      First of all, they're twins. You can do what you want to do with a twin more easily with less hammering the conrod bearings on  journals & piston pins. As a single approaches firing closer to TDC it's going to hammer the bearings.

       Why do you want to pull away & almost lug the engine. Why don't you not want to just downshift?

         I'm not preaching at you about shifting "wrong". Do what you want, but I'm just curious.

          I know, I know. It killed the cat, but satisfaction brought it back   

          I sort of understand this wanting to be able to putt around at very low RPMs. I've ridden a lot of shovelheads & it is a very cool feeling, on a well tuned & set up one, to be able to maneuver around at very low speeds in first gear without ever twisting the throttle (or putting a foot down) at all to above an idle & by just feathering the clutch in & out as necessary. But, again, they're not vertical singles. 950-1,000 was my idle RPM. I never was a "see how low it'll idle" guy.

     The Citroen D Models with Citromatic were also designed & set up to operate this way & were controlled hydraulically. You could park one without ever touching the throttle; only pressing & releasing the brake button. When properly set up, the car would just barely creep when the brake button was released.  I had one ID-19 & 5 DS-21s over my many years with these marvelous cars.

     

[Mac350]

       Why do you want to pull away & almost lug the engine. Why don't you not want to just downshift?     

This is part of my cruising grounds, it opens up in places but a lot of it is like this in Devon https://maps.app.goo.gl/yaoydLaFQUgyqxsE7

The hedges are tall and the road so narrow I have to slow right down for corners each time. I have to shift quite a bit anyway but I just want the widest possible usable rev range so i'm not constantly shifting. Maybe I should have got an automatic  nah just kidding. I was thinking low torque was a feature of this type of engine but starting to think i've got that wrong?

[AzCal Retred]

You have rather caught up to why modern engines are, well, modern. The long-stroke, 1935 design, fuel sipping, India-built-to-a-price Bullet makes around 23 HP & revs "reliably" to maybe 5500-6000 RPM. It pulls reasonably well from about 2000 RPM up to 4000-4500 before it tells you "Enough! Time to shift." and the vibraphone starts rattling your eyeballs. They don't like to be lugged or buzzed, just let them "run freely". A CB500x Honda makes 47 HP, pulls well from maybe 2500 to 9,000 RPM and redlines at 10,000 RPM. As a percent of usable operating RPM, the Bullet is at maybe (3500/6000=) 60%, the Honda at (7500/10000=) 75%, but over a rev range that's (10000/6000=) 160% greater than the venerable long stroke Bullet. That translates into more "gear overlap", where you have a choice of gears for a particular road speed, plus double the HP to play with. In my Bullets I often have to be content running at a speed the bike "chooses" for me. On hills many times there isn't enough ongawa to upshift to the next higher gear, just not enough overlap. To add insult to injury, the Honda has 6 speeds to carve all of this lovely power up with.

Does that make the Bullet bad? Absolutely not. The whole point of buying a brand-new 1935 antique is to experience the machine tech of that era. It's a very different "vibe" than anything sold today (except maybe 2CV's Big Twins). Enjoy it for what it offers. For the same money you can get a modern bike if performance is the criteria. 90 years of technical innovation guarantees a modern bike will perform better. But it won't put that biggo 1935 era grin on your face when you select the right gear for that hill, or chuff along a B road immersed in a calliope of machine sound.

Calliope:
1) the Greek Muse of heroic poetry
2) a keyboard musical instrument resembling an organ and consisting of a series of whistles sounded by steam or compressed air
With a name literally meaning "beautiful-voiced" (from kallos, meaning "beauty," and ops, meaning "voice"), Calliope was the most prominent of the Muses—the nine sister goddesses who in Greek mythology presided over poetry, song, and the arts and sciences. She is represented in art as holding an epic poem in one hand and a trumpet in the other.

[Adrian II]

A 500 single will have more torque than a 350, but intelligent gearbox use is still a thing. At least you have the smoother 5-speed box with a better spread of gear ratios. Maybe a BSA M21 with a lightened set of flywheels is what you need?  Also count the number of teeth on the gearbox sprocket, in your local riding conditions you might benefit from a smaller one, i.e. down from e.g. 16T to 15T. I understand Indian 350 Bullets are slightly higher geared than the old Redditch ones, lowering it would make the bike more responsive overall, albeit with some probably minimal loss of top-end performance.

That's a damn fine offer thank you very much and I may well take you up on it. Would the throttle cable I'd need to get then anyway work for the Wassell if I decided to get that later? Do you know which one of these it is? https://www.dellorto.co.uk/product-category/dellorto-motorcycle-carburettors-parts/complete-carburettors-dellorto-motorcycle-carburettors-parts/phbh-26-to-30mm/

The carburettor is this one, the 28BD: https://www.ebay.co.uk/itm/403255634948 although it now sports an alloy float bowl. Let me know where to send it.

I have had three different carbs on my 350, ALL of them were happy with a standard Indian 350 Bullet throttle cable intended for a VM24 Mikarb. For personal preference I use angled cable ferrules available from Dell'Orto (which also fit the PWK28 and the Mikuni!) and shorten the cable outers if needed. I also use a cable conversion for the cold start, again the same choke cable has worked with all three. At a guess the same throttle cable would work with the 626 Wassell clone, for the 928 which uses a larger body casting it might need a cable with a slightly longer inner (or you can shorten the outer).

SU carbs have been used successfully on motorcycles, but on TWINS, factory-fitted to some Triumph 6Ts in the 1950s, along with some aftermarket conversions in the 1990s, but NOT on singles. If you want a CV carb the one that's on there ought to be tunable (If I could just find my old tuning info...). Or I could try and find out what the CV29 settings are for the 350 UCE Bullets in India, they seem to work OK.

Ref the possible cylinder head leak, you can re-face the cylinder head to barrel joint faces with a sheet of wet and dry sandpaper over a chunk of plated glass if they need truing up. then just use a smear of Wellseal on a new head gasket, tighten the head nuts evenly when you re-assemble, then re-tightening is recommended after 500 miles.

[Adrian II]

Right, here is Ric's guide to tuning the BS CV29 carb. Bear in mind this the for the 500 engine, not your 350, but the same principles apply, so it can probably be scaled down, though jets are cheap enough for you to experiment with the 500 settings

   

Ric's CV Mikarb 29mm Tuning plus Slide Modification

    There has been a lot of activity recently on various other sites with regards to tuning the Electra X lean burn 500 but without incuring the expense of a larger carb.

    As a lot of this info has been compiled here over the last year or so among some postings not accessible to casual browsers, I thought I'd rehash the basics of what worked for me (before I went and spent a lot of money on a larger carb). Some info has been obtained from other sites, some of it no longer here as the posts have been cleaned during 'housekeeping'

    Feel free to add your own improvements

    The original idea of experimentation was to improve mid range performance , not top end performance, although I did end up with both. MPG has improved as this set up is a lot less restrictive than stock, but realistically the additional MPG obtained will never be recovered against the costs incurred, but it nicer to be able to stretch that distance between fill-ups.

    The Electra 29mm CV carb can still work fairly effectively on the bike providing its acompanied with a few other changes.

    The standard filter needs to be changed for its direct K&N replacement, the
    DU-0100, this will fit straight into the air box. The eliptical/circular hole in the baffle plates inside the box need to be opened up to allow a better flow of air inside the chamber. Remove a 2mm wide strip from each half of the box.

    Replace the standard downpipe with a Hitchcocks unrestricted one.

    Replace the standard silencer with a free flow unit.

    Adjust the carb mixture screw to around 4 turns out.

    Raise the needle up one notch to its highest position.

    Remove 0.8mm from the base of the slide - it may require a little more but this was the point at which mine seemed better than stock.

    Increase the main jet from 110 to 120. This was the largest size I found was needed on my bike when running a straight through exhaust. 117.5 may work as well if using a slightly restricted set up.

    A couple of hours of porting work to clean up the casting imperfections, (especially the exhaust)

    BR9EIX Iridium plug

Another modification was discovered by an Indian owner which improved throttle response. Read his cautions carefully

Crisp Punch: Ported throttle slide on a CV Carb with a first hand review
by Jay Prashanthon May 5, 20103 Comments

Ported CV Carb Throttle Slide vs Stock CV Carb Throttle Slide



Linearity was nice on the school bus you used to go to school in, but linearity on a motorcycle this side of the economuters can mean only one thing, boredom. I’m not suggesting liter class SBKs or ported two strokers for your daily dose of gonad juices here, I’m talking about how your daily ride 150cc motorcycle can put a smile on your face every time you whack open the throttle. Kicking off this tech post, I’m going to elaborate and review a simple mod on the CV(constant velocity) carburetor that can make your everyday commute just that tad bit exciting.

Let’s begin with understanding how CV carbs work, in a layman’s perspective, and why your engine doesn’t die out as you whack open the throttle on your 150cc Pulsar/Karizma or Unicorn. First of all, you need to remember that the advent of the CV carbs was simply to make the riding experience simpler and kinder by giving the carburetor more control than your right fist. It is therefore of no surprise that the dirt bike crowd simply shun the sluggish CV carbs for ultra responsive flat slides. The CV carb basically works by it’s slide operating on differences in vacuum created by the engine’s piston, instead of being connected directly to the throttle cable.

This is in complete contrast to round slide and flat slide carburetors, whose slides are connected directly to the throttle cable thus responding instantly to the throttle inputs your right fist gives it. The CV, on the other hand has a diaphragm atop it’s throttle slide that will regulate the speed/rate at which the throttle opens or closes. This, it does by gradually regulating the vacuum inside the carburetor and thus the movement of the slide. Hence, you can whack open the throttle on a CV carb throttle and still manage not to cause the engine to starve, which otherwise would have been the case if you did the same with a round/flatslide carb.

CV Carb Cutaway

Coming to the throttle slide on a CV carb, there usually are two or three ports/holes/orifices on the bottom of the throttle slide. On of these holes, the one which is in the center, accommodates the needle of the carburetor. The other hole(s) are basically vacuum ports, which are extremely important as they are the ports which are responsible for vacuum changes, and hence directly impact the working of the CV carb. The throttle slide modification in question is directly related to these ports.

What we essentially do in this modification, is we drill out the vacuum ports to a slightly larger diameter. For example, the vacuum ports on the Mikuni BS29 CV carb measures 1/16th of a inch in diameter. What we do is, we drill out the vacuum ports to 1/8th of an inch, effectively doubling it’s diameter. This doubling of diameter increases the flow of air through these ports by 4 times. Thus, when you whack open the throttle of a motorcycle that has a ported throttle slide in it, this time, the rate of change in vacuum will be a lot quicker than that in the stock slide. As this rate of change in vacuum is quicker, your throttle response goes up massively and your motorcycle feels much more livelier. Of course, you won’t be going any faster but you’re motorcycle will certainly feel a lot more agile and more responsive to your throttle inputs.

Chinmay Dangre or CorePower Motorcycles sent me a ported throttle slide which I fitted on my Stage 1 Royal Enfield Bullet Machismo LB500 last Sunday. Riding down the Airport road in suburban Bangalore, I immediately felt a marked difference in the way my Bullet responded to throttle inputs. As I run on a richer pilot mixture to prevent popping from my goldstar muffler, my initial throttle response is usually sluggish/lumpy on the stock CV carb. But with the ported throttle slide in my carb, the initial throttle response became a lot more smoother and more controllable. I could literally control the throttle down to the last mm of it’s play, which was hitherto an impossibility on the more sluggish stock CV carb.

Since my motorcycle runs on a free flow intake and exhaust, I have ample low end torque. This ported throttle slide has enabled me to control and use this torque more efficiently. With the ported throttle slide, I can now ride the torque curve for say till the first 1/4th of the throttle opening, like say on a STD350 and thump along nicely, and that is quite a statement to make. Once I whacked open the throttle beyond the initial 1/4th throttle, my bullet simply lurched forward, quite unlike the measured, linear way in which it used to gather speed before. All in all, my Bullet now feels a lot more lively and I’m enjoying the improved throttle response to the hilt.

For people interested in porting their throttle slides to make their bikes more responsive, you can do so by
1> Drilling out your existing throttle slide. This requires a very steady drilling hand as it is extremely easy to burr the slide and thus destroy the vacuum ports beyond repair. Also, care must be taken to make sure that you handle the diaphragm atop the slide very gently as the extremely delicate diaphragm is prone to tearing if mishandled.
2> Contact Chinmay Dangre at macasp@gmail.com and specify your motorcycle model. Chinmay will then port a new throttle slide and ship it over to you. Then, you can ask your mechanic to do the install of the ported throttle slide or if you’re a DIYer, you can do it yourself if you’re confident of your way around carburetors. For people in Pune, the fitment can be done at Chinmay Dangre’s workshop. For pricing details, please contact Chinmay directly.

This mod will work on all motorcycles that run on CV Carbs, and these include, but are not limited to, Yamaha Gladiator/Fazer/FZ16, all Bajaj Pulsars including the Pulsar 135, Bajaj Discover 125 and 135, Honda Unicorn, Suzuki GS150R, Hero Honda CBZ Extreme, Karizma, all Royal Enfield Bullet UCEs exceot the Classic 500, Royal Enfield Thunderbird LB350 and Royal Enfield Machismo LB500.

[Mac350]

Does that make the Bullet bad? Absolutely not. The whole point of buying a brand-new 1935 antique is to experience the machine tech of that era. It's a very different "vibe" than anything sold today (except maybe 2CV's Big Twins). Enjoy it for what it offers. For the same money you can get a modern bike if performance is the criteria. 90 years of technical innovation guarantees a modern bike will perform better. But it won't put that biggo 1935 era grin on your face when you select the right gear for that hill, or chuff along a B road immersed in a calliope of machine sound.

Calliope:
1) the Greek Muse of heroic poetry
2) a keyboard musical instrument resembling an organ and consisting of a series of whistles sounded by steam or compressed air
With a name literally meaning "beautiful-voiced" (from kallos, meaning "beauty," and ops, meaning "voice"), Calliope was the most prominent of the Muses—the nine sister goddesses who in Greek mythology presided over poetry, song, and the arts and sciences. She is represented in art as holding an epic poem in one hand and a trumpet in the other.

Where's the like button on this forum    No doubt this is a bike with more than enough character to trump any shortcomings, I just need to learn how to get the best out of it and I'm sure I'll be happy. And when it ran ok coming bringing it home it was full grin the whole way. I even like the solid way it goes around bends, the suppleness of previous bikes suspension is missing but even that isn't missed. But best of all the tinkering is so much more enticing than previous bikes. The Snidal manual arrived yesterday and I'm reading it from cover to cover before asking more questions. Lots of great insight gleaned already and it features the BS29 carb though he just calls it the "MIK CV carb". He makes it sound like a decent carb. I've realised why my main jet doesn't look like the pictures elsewhere, I removed the "jet block" with the jet on it and thought it was on piece. I'm going to clean it out, put the needle clip back where it was, remove the filter and see how it goes following instructions in the book.

[Mac350]

Maybe a BSA M21 with a lightened set of flywheels is what you need? 

Oh yes. https://www.youtube.com/watch?v=8-PIY4lAfv8

I can see how this could easily get out of hand 

[Mac350]

The carburettor is this one, the 28BD: https://www.ebay.co.uk/itm/403255634948 although it now sports an alloy float bowl. Let me know where to send it.

Just giving the CV one more chance and i'll do that thanks. The dellorto has masses of info online though all about very different engines I guess its still relevant. But if i can get the CV working adequately I have a lot of other things i should be doing before throwing another carb into the mix. I'm redesigning my house around having a pet bike to take care of. Not kidding. I don't have a usable garage for this so I'm putting patio doors on a back room and turning that into a workshop. It was in the works to do similar anyway but this has solidified the plan. So i need to get the bike usable for now, do a full proper service. Actually use it a bit in case I forget why i bought it. Then sort out the winter space for it. It has no rust on the frame and I think its always been indoors and a fair weather bike so i dont want to leave it under a plastic cover over winter.

Or I could try and find out what the CV29 settings are for the 350 UCE Bullets in India, they seem to work OK.

It would be ideal to try that first. I think the clean looking air filter must be more blocked than it looks, should have just ordered a new one. And I definitely should have realized the link if it was running better with the split hose, though with the enricher on. Early days.

Ref the possible cylinder head leak, you can re-face the cylinder head to barrel joint faces with a sheet of wet and dry sandpaper over a chunk of plated glass if they need truing up. then just use a smear of Wellseal on a new head gasket, tighten the head nuts evenly when you re-assemble, then re-tightening is recommended after 500 miles.

The head studs and on the exhaust are the only rusty bits. I'll spray them before removing and a bit of wire brushing. I have an impact wrench, in fact 2, a monster one that has never failed to remove a nut and a smaller 3/8 one i'd try first on this... I often wonder what is better for iffy studs you really don't want to snap, a spanner increasingly pulled but having the one sided twist to it and from experience you still can't tell its going to snap something until its snapped. just feel it go soft and off it comes "oh shit". Or less feel with an impact gun but at least shocking might break the rust and the pull just goes around the nut equally. Any experience?

[Mac350]

Maybe a BSA M21 with a lightened set of flywheels is what you need? 

Hell yes https://www.youtube.com/watch?v=nvbXfLC-HUI

[richard211]

The BS26 is the correct carb for the later model AVL 350 and people started switching to the BS29 carb from the UCE 350 because it was around half the price of a BS26 carb in India. When I had a BS29 carb on my AVL350 (the motorcycle was sold to me like that), it ran fine on flat roads, but while travelling up hill, the engine would bog down immediately and would be struggling even in second gear (5 speed) while a stock 350 IB would chug along effortlessly in 3rd gear. I had not port matched the cylinder head to the BS29 carb. The inlet port on an AVL 350 from memory was around 27 mm. What I found was that the BS29 was good for highway cruising 80 - 90kph, but lost out on the low end torque, the BS26 was the best all round carb and the IB VM24 (modified flange) had better low end response all the way up to 70-75 kph.
 
 The 350 AVL came with a crankshaft that weighed 8kg (factory lightweight crankshaft) which allowed the engine to accelerate faster, but the engine will not be happy being used at low rpms in a higher gear. So if one wanted to lug the engine around, the heavier crankshaft would be a better choice but will have a slower acceleration.
 
 Also check that there is a sufficient spark at the spark plug, the CDI unit setup had the benefit of being able to be started without a battery, but had a lower spark output, so if the spark plug gap is too big, under load the engine will loose power.
 
 The BS29 carb is one of the more common carbs available in India, since it was used by multiple motorcycle manufacturers and while they looked similar externally, but they were different internally.

[Mac350]

confession time. I was going by the look of the carb compared to pictures I found online as I couldn't see any number on it. It looks nothing like this BS26

or any picture I can find of a BS26 but looks exactly like this and every picture of the BS29


I just measured the carb and its 26mm  Then i took a magnifying glass to it and found faintly pin punched numbers and sure enough its the BS26  Sorry about that. I should have learnt to cross check assumptions with measurements by now.

According to the retired model catalogue the pilot and main jets 15 and 110 I have are standard. I just need to get it back together and take out the air filter from the box temporarily and see what its like. If its just a bit lean then I guess I just want to get a decent cone filter and tweak it from there as required. Are K&N cones really worth £50?? Its on a 45mm outer diameter of the carb and I can get either 43mm or 46mm inner diameter cones any idea if i should go small or larger and pinch down? Really can't afford to order 2. If they are good I'm willing to pay that to match the more free flowing exhaust. I would certainly like to remove the airfilter boxes and battery box so do want a cone

For info the inlet on the head is 28mm.

[Mac350]

The BS26 is the correct carb for the later model AVL 350 and people started switching to the BS29 carb from the UCE 350 because it was around half the price of a BS26 carb in India. When I had a BS29 carb on my AVL350 (the motorcycle was sold to me like that), it ran fine on flat roads, but while travelling up hill, the engine would bog down immediately and would be struggling even in second gear (5 speed) while a stock 350 IB would chug along effortlessly in 3rd gear. I had not port matched the cylinder head to the BS29 carb. The inlet port on an AVL 350 from memory was around 27 mm. What I found was that the BS29 was good for highway cruising 80 - 90kph, but lost out on the low end torque, the BS26 was the best all round carb and the IB VM24 (modified flange) had better low end response all the way up to 70-75 kph.
 
 The 350 AVL came with a crankshaft that weighed 8kg (factory lightweight crankshaft) which allowed the engine to accelerate faster, but the engine will not be happy being used at low rpms in a higher gear. So if one wanted to lug the engine around, the heavier crankshaft would be a better choice but will have a slower acceleration.
 
 Also check that there is a sufficient spark at the spark plug, the CDI unit setup had the benefit of being able to be started without a battery, but had a lower spark output, so if the spark plug gap is too big, under load the engine will loose power.
 
 The BS29 carb is one of the more common carbs available in India, since it was used by multiple motorcycle manufacturers and while they looked similar externally, but they were different internally.

Great info thanks. You're not the first person on this thread to say 26mm is a good match. I'll keep trying to get this BS26 to work then. I don't think I'd want to live with struggling up hills in 2nd gear. Presumably having a 26mm carb on a 28mm port isn't an issue like it would be the other way around.

Now I'm realising there are 2 types of BS26 and I've got the one that shares most parts with the BS29 (according to the retired model catalogue) I realise I might be better off buying a BS29 from india for £55 delivered instead of paying £15 for a float bowl O ring that it looks like it could do with and I'd get a diaphragm that isnt available separately here, a float needle, all the other matching o rings, spare float...

[Adrian II]

Thanks Richard,

I was actually going to ask you what the correct carb settings should be.

Also check that there is a sufficient spark at the spark plug, the CDI unit setup had the benefit of being able to be started without a battery, but had a lower spark output, so if the spark plug gap is too big, under load the engine will loose power.

That sounds about right, the spark plug gap on a battery and coil ignition bike would normally be 0.025", but for magneto use the same plug would be gapped down a bit to 0.018" - 0.020" Can't do it on Iridium plugs, though!

*************************

A 28mm port down to a 26mm carb should be no problem, if you WERE obsessed about it (nervous twitch!) you could make a carb spacer from 8mm Tufnol with a slightly tapered big hole in the middle which would smooth the flow nicely. Should be room to squeeze one in, especially if the airbox is going to be removed. This was for a 500 head but it gives you an idea.



There are loads of generic el-cheapo Chinese-made cone filters which will do the job, just make sure you pick one which is NOT for a pit bike as these can be a bit bunged-up in the middle, free-flowing is what you want. 46mm will squash down onto a 45mm outer stub happily enough with a good slimline jubilee-oid clip.

But if those Devon lanes are not too dusty, how about one of these instead of a cone?



A.

[tooseevee]

Right, here is Ric's guide to tuning the BS CV29 carb. Bear in mind this the for the 500 engine, not your 350, but the same principles apply, so it can probably be scaled down, though jets are cheap enough for you to experiment with the 500 settings

      I can't Quote Rick in this response because  your quoted part doesn't show up when I quote you, but I remember all this from when I was tuning my BS 29 BEFORE I had the Ace headwork done & changed to a Mikuni TM 32. A lot was discussed about AVLs & CV & flat slide carbs back between 1999 & 2020. Not so much now.

     What I took (& take) issue with Ric on is:

      Mixture screw turned out 4 turns &

       Raise the needle to it's highest position (needle in bottom notch).

       It just seems to me that his Pilot Jet must have been way wrong for his engine to run right with those settings.

        And for Mac350: If I haven't mentioned this before remember it's called the UCAL BS-29.
https://www.google.com/search?client=firefox-b-1-d&sca_esv=2ca6f23d8cc3e1e1&sca_upv=1&q=ucal+bs29&udm=2&fbs=AEQNm0AVbySjNxIXoj6bNaq7uSpw-2eW7KIQ8H4T_tEPJYsPzOi5GKsV0RKGmy84LfyUxrl-4_0AusV0IdjeUAdX2KBg7BmnGLOak5d-z-_u-BD5mN13FgBnNWDvju7R9DTlWNidOrJflM1JuVtiWYZDkHFOJzhjFWWukocdFSx3yN5TzfLggWRnI4Aa-8EhEIZUfHR_WMFwmbeNhwTWDi8XltL7qhh3uw&sa=X&ved=2ahUKEwjKk9SfnouIAxVXAHkGHduaKmsQtKgLegQIGRAB&biw=808&bih=387&dpr=2.07

 

[Adrian II]

I dimly seem to recall that both the UCAL and Mikarb versions of the 29mm CV carb were used at various times, not sure if there were any major differences. The 500 AVL Classic was launched somewhat later than the Electra-X, different carb suppliers used at different times?

I could be way off about this, of course!

A.

[richard211]

I dimly seem to recall that both the UCAL and Mikarb versions of the 29mm CV carb were used at various times, not sure if there were any major differences. The 500 AVL Classic was launched somewhat later than the Electra-X, different carb suppliers used at different times?

I could be way off about this, of course!

A.

 Earlier Mikuni and UCAL were a joint venture and later on split up, resulting in UCAL having to take off the Mikuni branding off their products and rebranding the carbs as UCAL.

[Paul W]

I fitted a similar air filter to the one linked to. It fits over the short bellmouth on my WASSELL. It seems to filter well enough and certainly isn’t restricting to the airflow.

https://www.ebay.co.uk/itm/276354704021

[Adrian II]

I had something similar on the 350 briefly, made by Ram-Air. It's a bit scorched on the inside after a couple of back-fires!

A.

[Paul W]

Mine was fitted possibly five years ago.

[Adrian II]

Hmm, it's all gone quiet again. 

You still there, Mac350?

A.

[Mac350]

Hmm, it's all gone quiet again. 

You still there, Mac350?

A.

Hi yes still here, had a manic week ripping out an old shed and fence and building a new larger fence with gates with now a 3x3m marquee safely behind it to use as a bike garage, just finished. Until today I just had a small back yard space I couldn't even turn the bike without dragging the back wheel around but was a bit of a nightmare to reverse out of too and no covered area to work on it. Now I have a 6m x 3.5m fenced in space with a 2.3m high fence and 3x3m of it is a covered enclosed area. Its a bit leaky in places but it only cost £20 used so I can splurge on some gaffer tape. Will add an LED strip and a radiant heater. Now I can wheel the bike in and out easily it will be much nicer to jump on for a quick ride.

Next stage though will have the marquee become an outdoor wood workshop while I turn the back extension into a proper workshop, its about 20sqm so not far off a double garage. Bit of a job though, strip the flat roof off and replace probably all the wood, the wood windows are shot and I'll replace the floor with concrete so i'll be stripping it back to just the walls. Just the weather stopping me again now, the marquee will help a lot for that though and safe enough to leave some tools in. Bike is chained up out the front under a cover for now. Will be great to purpose make this workshop, I can make sure I've got a 16amp supply direct from the consumer unit so I can weld at the same time someone else puts the kettle on and with a concrete floor I'll apply some sort of industrial garage coating. I'll need to get a bike lift that can rotate and move around with the bike on it ideally

The extension was going to be left how it was as a bedroom with en suite (though it needed a full refurb anyway), in case needed for a granny flat but this old bike needs it so it sort of will be doing what we thought it would

[Adrian II]

That's a lot to take on!

A.

[Mac350]

i'm like a coiled spring at this point, been putting it off for years but now the plan has solidified thanks to having this bike I'm just cracking on and getting it done. At least doing it myself I don't have delays waiting for people. Neighbours can't believe how fast the fence went up after seeing the dilapidated one for years.

Relaxing with some video on youtube I watched a this one on the new classic chrome, looks very similar to the machismo https://youtu.be/ygTrZIuEZvc?t=1229 fair play to enfield for managing to get around the emission issue while still keeping a fairly unique appeal. I was wondering what the point was of an enfield with a modern engine that takes care of itself and starts on the button but he seems to be enjoying it just the same despite not having to get oily fingers. Funny though when he says its got hardly any technology and is pleased about it. Buts its got fuel injection, ABS and a headlight that runs off a battery for gawds sake   

[Mac350]

Actually its hard to find bike videos that aren't people advertising new bikes, true on other topics as well, youtube has become a continuous advert. Are there any particularly good channels about older Enfield's that aren't just shilling stuff?

[allanfox]

This guy isn't far from me in Suffolk, musings about his stable of Enfields, mostly a good watch with a cuppa!

https://www.youtube.com/@Volcanicbrown1878

[El Saif]

This is the OEM carburetor on my 2004 350cc Thunderbird kick start pnly.

The card has not been touched.

The fuel line from the tank to the carburetor rotted away

[Adrian II]

Same carb as on this 350 Thudnerbird engine for sale at Hitchcocks'.

https://accessories.hitchcocksmotorcycles.com/53763?cont_page=Engines

Note this one all the primary cases, alternator and some of the CDI parts as well, all for £100 +VAT. Quite the bargain by Mr H's standards. 

A.

[Mac350]

This guy isn't far from me in Suffolk, musings about his stable of Enfields, mostly a good watch with a cuppa!

https://www.youtube.com/@Volcanicbrown1878

Good recommendation thanks. Funny the first one I clicked on I thought i recognised the lanes and sure enough I know them well. I'm from the east edge of Ipswich originally and we used to go for runs out this way on bikes and cars when I was a boy racer https://www.youtube.com/watch?v=DlYQWYkwj0g its a nice part of the country.

[Mac350]

Same carb as on this 350 Thudnerbird engine for sale at Hitchcocks'.

https://accessories.hitchcocksmotorcycles.com/53763?cont_page=Engines

Note this one all the primary cases, alternator and some of the CDI parts as well, all for £100 +VAT. Quite the bargain by Mr H's standards. 

A.

The other leanburn engines are way less than the other bits for sale as well. If it wasn't for the £60 postage I'd buy it just in case, practice rebuilding it and mount it as wall art until I need it. I'm finding the disinterest in this AVL engine very strange. I watched an official enfield channel history of the bullet and they just skipped over the AVL years. But thats fine by me if it means bargain parts.

[Mac350]

I like this way to learn how to do something rather than following a manual, and I've not got to the oil change yet. Not quite as simple looking as dropping the oil out and replacing in other bikes. Is all this true for the AVL same as the CI engine?

https://www.youtube.com/watch?v=4hUylyXwm2k

[tooseevee]

I'm finding the disinterest in this AVL engine very strange. I watched an official enfield channel history of the bullet and they just skipped over the AVL years.

    I found that also, in the ones I've watched. They're like an orphan child who doesn't know who its parents were.

[Adrian II]

The oil filter is shorter and fatter on the AVL, but it's pretty much the same procedure.

As for the lack of interest in or antipathy towards the AVL design, at least outside of India, is that they're well... different. Not REAL Bullets?Top end finning is sparse, on all but the early ones you have that weirdo CV carburettor, and that timing cover, it's a bit CHUNKY, innit? People had forgtten or didn't know about the square oil pump housings on the older RE models.



Then we have the RE Thunderbird styling, whose side-panel and strange tool box design went onto the Electra-X, more don't like it-ism. The US importer persuaded the factory to put the 500 AVL engine and gear box in a traditional Bullet tinware equipped rolling chassis but Watsonian-Squire couldn't be bothered with it in the UK. Then you have the damage to the models' reputation caused by sprag clutch and premature big-end failures.

Good, more for us then!

Tomorrow (Saturday) is the VMCC autojumble in Cheddar, will you be crossing the border into Somerset?

A.

[Mac350]

The oil filter is shorter and fatter on the AVL, but it's pretty much the same procedure.

thanks

As for the lack of interest in or antipathy towards the AVL design, at least outside of India, is that they're well... different. Not REAL Bullets?

I would have believed that aspect other than I see zero complaining about the unit engine with overhead cams and fuel injection being unreal bullets. I can well believe I missed that period of mourning which surely happened at some point but now all I see are people like mr volcanic brown who clearly knows a real bullet when he sees one, enthralled https://www.youtube.com/watch?v=QQdF-1pJLak with what even I'm looking at and thinking they are no more an enfield bullet than the new Minis have any more than the faintest visual relationship with the Longbridge original, but no one is willing to see the AVL engine as a real bullet still?

Just looking at the Thunderbird history and they kept making them so can't have been that style was the issue. From the wiki page:

First-generation AVL 5-speed engine Royal Enfield Thunderbirds were produced from 2002 to 2005. These consisted of CDI only as part of its electricals. The bikes were reliable and would start without the need of a battery, in company stock condition, making it more reliable than the Cast-Iron or the UCE Royal Enfield that needs a battery to start. The chassis were strong-thick-heavy-gauge used from the old cast iron Enfield's like the 350s/500s Royal Enfield Lightning, Deluxe, Standard Bullet, Machismo etc.

In 2009, the AVL semi-unit engine was replaced with the new 346 cc unit construction engine (UCE). The bike was renamed Thunderbird Twinspark owing to the twin sparkplugs in the UCE. Lighter gauge chassis to reduce weight were incorporated in order to improve performance. This led to a downgrade in terms of quality strength for the UCE Thunderbird as compared to the AVL Thunderbird

the 5-speed AVL aluminum engines with left side gear shifter were produced from 2002-2009 (approx less than 7 years). This makes the Royal Enfield AVL engines rare and quite the collectors item. 

Finally a bit of love for the AVL. Also says "The AVL engine had a higher compression and shorter stroke when compared to the Cast Iron Engine." Is that right? The stroke seems to be quoted as 90mm same as I'm seeing for the CI engine

Tomorrow (Saturday) is the VMCC autojumble in Cheddar, will you be crossing the border into Somerset?

A.

I'm often in Somerset but not today. Had a quick look into it and have to say I found this off putting. Is that the most enticing bargain they could find to make it seem worth going?

[Paul W]

I suppose my 350 Bullet Electra (iron barrel engine, non distributor, TCI ignition) is an even rarer beast than the AVL powered Electra-X. The chap on the counter at Hitchcock’s had trouble acknowledging it when I first went there to buy service parts for it. Being an kickstart only bike it’s an alternative way of upgrading the old points ignited engines without the disadvantages of the electric start sprag clutch problem.

[tooseevee]

I like this way to learn how to do something rather than following a manual, and I've not got to the oil change yet. Not quite as simple looking as dropping the oil out and replacing in other bikes. Is all this true for the AVL same as the CI engine?

https://www.youtube.com/watch?v=4hUylyXwm2k

     Speaking to that video, I enjoy seeing the same hand pin-striped tank as my 2008 AVL Classic has on an "older" RE. I always wonder if the same man striped my tank.

       I'm an incurable "vintage guy". I've never bought a brand new motorcycle in my life & only ONE brand new car.

        Oil changes are simple. Don't let any of it worry you.

[Mac350]

     Speaking to that video, I enjoy seeing the same hand pin-striped tank as my 2008 AVL Classic has on an "older" RE. I always wonder if the same man striped my tank.

       I'm an incurable "vintage guy". I've never bought a brand new motorcycle in my life & only ONE brand new car.

        Oil changes are simple. Don't let any of it worry you.

Not worried but do want to get it right. He has an interesting video about the reason for the right oil for cold weather. https://youtu.be/c6qn5-itwI8?t=34 Something to do with a bypass valve that they stopped including in india due to usually warmer temperatures. Not sure if the AVL engine has that valve? Or if the improved oil pump needs it?

I bought a new Honda 600 Hornet 20 years ago because second hand prices were just a few hundred pounds less than new. But cars I just buy the cheapest thing that will do the job. After having fast bikes no affordable car is very interesting so I just having something big enough and dented enough that I don't need to worry about it getting scratched when i use it as a van down country lanes.

[AzCal Retred]

"He has an interesting video about the reason for the right oil for cold weather. https://youtu.be/c6qn5-itwI8?t=34 Something to do with a bypass valve that they stopped including in india due to usually warmer temperatures. Not sure if the AVL engine has that valve? Or if the improved oil pump needs it?"

https://accessories.hitchcocksmotorcycles.com/core/media/media.nl?id=238414&c=1062795&h=ggDB3S3jRfE-uMVzXpHwJW7RjSL4Uag3lEA67_9WuMIB9m7P&_xt=.pdf

Page 35 of 234 shows the AVL oiling system. 15W40 recommended. Gear pumps are laid out like the old plunger pumps were. Maybe a Hitchcock's PRV would help, Others will have a better take on it. The old plungers got a weaker disc spring to "allow relief on overpressure" by letting the disc move away from the sealing surface. That wouldn't really apply to the gear pumps. In Olden Tymes the straight 50W in England in the winter needed a relief valve. Modern multigrades, not so much.


ffff

[Adrian II]

I think The Lore was straight 40 in summer, change to straight 30 for winter riding.

Also says "The AVL engine had a higher compression and shorter stroke when compared to the Cast Iron Engine." Is that right?

Half right. Higher compression, yes, to make the lean burn work, but the same stroke as the iron barrel Bullets. What might cause confusion is that the AVLs have shorter con-rods, 160mm centres as opposed to 177(?)mm. This and a shallower piston results in a noticeably shorter cylinder barrel. The overall engine height is about the same with the taller cylinder head.

I'm often in Somerset but not today. Had a quick look into it and have to say I found this off putting. Is that the most enticing bargain they could find to make it seem worth going?

A mistake/unfair to judge a whole event by one photo. Today after a good mooch around there I found THIS lot of older Bullet stuff.



Got chatting to the seller, a wonderful old boy from Exeter, and it soon became clear he was asking old-school prices, I think his stall must have time warped in from 20 years ago. Anyway, long story short, I came away with a pile of Redditch Bullet stuff, a pair of early 500 JS Bullet crankcases, timing cover with oil pumps, 500 alternator crankshaft and a pair of alternator chain cases, the whole lot for £130. Another pair of that type of crankcases alone in worse condition (which I sold on and later regretted doing so) cost me over £400 at A Well Known UK RE Parts Specialist. I have to admit I didn't see any 350 AVL stuff, though.

A.

[El Saif]

My Royal Enfield Thunderbird 350cc AVL kick start only was bought new in New Delhi in 2004. It came with the optional disc brake for an extra Rs 500.

Indian riders disliked the sound of the AVL engine as they preferred the thump of the cast iron Bullet engine.

The Royal Enfield Thunderbird 350cc AVL kick start only was sold as an upmarket market bike compared to the Bullet. The Thunderbird has a fuel gauge and a rubber coated gear lever to protect the shoes of an office worker rider.

The front tyre is ribbed.

[Mac350]

A mistake/unfair to judge a whole event by one photo. Today after a good mooch around there I found THIS lot of older Bullet stuff.

Looks like a great haul for the money. I have to keep away from places where I could buy lots of stuff I have no space for but one thing it might have been worth going for is i'm struggling to find a open face helmet that isn't huge. Did you see any older helmets for sale? I'm not sure any currently road legal post BS 1984 helmets were very slimline but the latest ones are comical looking.

[Adrian II]

I think the traditional Jet helmets are still around. My day-glo black one needs replacing, so I'll be off to the bike gear shop in Christchurch soon to see what's available.

A.

[tooseevee]

I think the traditional Jet helmets are still around. My day-glo black one needs replacing, so I'll be off to the bike gear shop in Christchurch soon to see what's available.
A.

      If I was forced by my State to wear a helmet, I might consider an old Biltwell.

[Mac350]

I think the traditional Jet helmets are still around. My day-glo black one needs replacing, so I'll be off to the bike gear shop in Christchurch soon to see what's available.

A.

Good luck finding anything that's not massive. It seems like the latest ece 22.06 has made them worse than the 22.05 so I've managed to find a recent used one that's 22.05, a DMD vintage. Looks lower profile than the newer DMD retro but waiting for it to arrive. My full face will do but now I'm not riding flat out everywhere seems like an open face would be a nice change but there's only so much ball head I can live with.

Now I've got a covered space to house and work on the bike I've got back to it. This bike even smells perfect when I go in I get hit with nostalgic oily perfume. My wife is doing well not to be jealous considering I'm spending more time and money on the bike than her just now. But I've still not got it running right. As the breather system was full to overflowing with mayo seems for sure the old filter was clogged by it despite looking fairly clean. (I'll do the breather to chain oiler mod whatever I end up doing filter wise.) So i removed the filter and running without it its back to how it was when I bought it and it had a split intake hose. IE Works great with the enricher on all the time. Any idea what the extra fuel is put in by that compared to additional jet size to have the same effect?

In case the happy medium is the restriction of a normal filter I've ordered a standard air filter to try that as I feel like I'll have a baseline to improve on if i can just get it working right in standard set up. Worth it for £10. If that works I'll feel like the carb is ok and just needs adjusting. 

It does idle fine with the enricher off but following the idle mix adjust instructions in the Snidal book I'm hardly getting any change with the adjusting screw. I bought a cheap inductive tachometer that wraps around the HT lead and it barely shows 20-40 rpm changes until its fully closed and the engine cuts out. I'd already tried removing the adjusting screw and using carb cleaner as suggested but I don't have compressed air to give it a good blow. Could this be the issue with this carb?

It ran terrible at one point and i realised I'd removed the plug cap to test the resistance and it was just 1/4 turn off being tightly screwed back in was enough to misfire and burp. I trimmed the HT lead and put a new NGK cap and new plug on. Now the bike starts ridiculously easily hot or cold, it feels very eager to run. Now I'm used to hearing the engine I can hear nothing from the bottom end and just some top end clatter. Tappet adjustment next after I get it running right though if that could be part of the problem maybe I should do it now?

I checked compression and was 135psi most forum posts seeming to say thats fine.

Just waiting on the filter now

[Adrian II]

Tappet adjustment won't make a lot of difference if they're a little on the loose side. Too tight is another matter, but as you're getting good compression, adjustment that can wait a while if needed.

My PHBH28 Dell'Orto is still sitting idle, I will ask a contact in India if he can find out the exact jet settings for it as used on the early A350 Machismo.

A.

[Mac350]

Tappet adjustment won't make a lot of difference if they're a little on the loose side. Too tight is another matter, but as you're getting good compression, adjustment that can wait a while if needed.

My PHBH28 Dell'Orto is still sitting idle, I will ask a contact in India if he can find out the exact jet settings for it as used on the early A350 Machismo.

A.

I haven't forgotten the offer thanks again. However I've just bought the engine at Hitchcock's you pointed out, coming with another carb though its another CV of the same age which might be no better, but people seem to report that these carbs are usually good (better combustion and acceleration apparently - http://www.enfieldmotorcycles.in/2010/05/royal-enfield-machismo-350-cc.html ) so I'd be unlucky to have both not working. The BS26 seems rare to find and I've been convinced away from having a bigger carb than needed.

Plus having the engine to play with at my leisure as well as the rest of it for spares. Seems silly not to for the price. Can imagine regretting not buying it more than regretting buying it. My bottom end and gearbox and clutch seem great so far. Having a spare top end I can fettle without being off the road seems like a great idea. I read about lapping to go without a head gasket the other day, sounds worth doing. I could polish up the spare cases to see how that looks.

But I've got a lot to do on the house first. Will use the carb and take the head and barrel off for a look before putting it away for a bit.

Before I do though how likely am I to manage to do a compression test without a kickstart? Just wedge the engine somehow and use a ratchet on the crank? would be good to see what is before i touch it, to make sure what I've done is an improvement.

Has anyone managed to put a small battery in here? https://accessories.hitchcocksmotorcycles.com/core/media/media.nl?id=478944&c=1062795&h=GtpiJ0Dz-eNOLIYkI2vpHsI5TDaUcHt7FLOvzo25QxuAqMlw

[Adrian II]

Before I do though how likely am I to manage to do a compression test without a kickstart? Just wedge the engine somehow and use a ratchet on the crank? would be good to see what is before i touch it, to make sure what I've done is an improvement.

Big spanner on the alternator nut, though be careful it doesn't come undone. IF it does, you can try THIS!

https://www.youtube.com/watch?v=-RaIJKogh6w

Has anyone managed to put a small battery in here? https://accessories.hitchcocksmotorcycles.com/core/media/media.nl?id=478944&c=1062795&h=GtpiJ0Dz-eNOLIYkI2vpHsI5TDaUcHt7FLOvzo25QxuAqMlw

Why do you want to put a battery in the primary chain case?

A.

[Mac350]

Why do you want to put a battery in the primary chain case?

A.

If i went nuts trying to be as minimal as possible it looks like i could hide a battery in there rather than the toolbox and get rid of both the air filter boxes, the battery box and toolbox. Doubt it would suit the rear end of the current bike I have as a want to keep a pillion seat so need to keep the rear mudguard, though saying that do i?....  but I'm already thinking about building another bike around the spare engine and I haven't got the first one running right still 

[Mac350]

Big spanner on the alternator nut, though be careful it doesn't come undone. IF it does, you can try THIS!

https://www.youtube.com/watch?v=-RaIJKogh6w

His bench is like mine unfortunately, just push the next thing onto it to clear some space. I occasionally spend an hour putting everything away but it lasts no more than a day before its like that again

[Adrian II]

His bench is like mine unfortunately, just push the next thing onto it to clear some space. I occasionally spend an hour putting everything away but it lasts no more than a day before its like that again

Tell me about it. 

My AVL hybrid currently has a small AGM battery mounted under the swinging arm pivot. I don't think there's a lot of room for anything much over 1/2AH in the chain case! Pretty hostile environment for a battery, too.

Bear in mind that your ignition and your headlight are already battery-less, you could try replacing the stop/tail, indicator, side light and speedo bulbs with LEDs, then you could quite possibly get away with running a Lucas motorcycle capacitor or similar instead of a battery. A Boyer Power Box is a reg/rectifier unit incorporating a capacitor, though with the price of generic reg/rectifiers being so low, it's a more expensive way of doing it.

A.

[Mac350]

Tell me about it. 

My AVL hybrid currently has a small AGM battery mounted under the swinging arm pivot. I don't think there's a lot of room for anything much over 1/2AH in the chain case! Pretty hostile environment for a battery, too.

lol I didn't even realise the clutch is in where I'm looking, thats the point I'm still at  I tried just reading the Snidal book yesterday, he claimed it would be good for newbies but its clear he never had a newbie test read it as he mentions a lot of stuff and I just don't know what he means. And it desperately needs more diagrams. It has numbered exploded diagrams but no list of what the numbered parts are. I feel like I need to do an apprenticeship, look over someone's shoulder while they do one, then have someone look over my shoulder while I do one.

The spare engine arrived already largely dissembled which is probably good as they could have tested all the parts before sending, hitchcocks said they get them from a trusted source in India. But I'm looking at parts with little idea what they, hey ho! I'll go and try the new carb now, can't think what else could be the problem so i hope its the carb.   

[tooseevee]

 If that works I'll feel like the carb is ok and just needs adjusting. 

It does idle fine with the enricher off but following the idle mix adjust instructions in the Snidal book I'm hardly getting any change with the adjusting screw. I bought a cheap inductive tachometer that wraps around the HT lead and it barely shows 20-40 rpm changes until its fully closed and the engine cuts out. I'd already tried removing the adjusting screw and using carb cleaner as suggested but I don't have compressed air to give it a good blow. Could this be the issue with this carb?

It ran terrible at one point and i realised I'd removed the plug cap to test the resistance and it was just 1/4 turn off being tightly screwed back in was enough to misfire and burp.

     All this seems to me to point to incorrect Pilot Jet.

      I'm not familiar with the carb you have, but the engine should idle correctly with the mixture screw (whether it's an Air or a Fuel Screw) screwed Out 1 & a 1/2 turns from gently bottomed out. And if the pilot is correct, you should be able to blip the throttle without it dying. THEN work on needle height.

     You've gotta work step by step, last being Main Jet, One thing at a time.

      I've had the feeling all along in your story, that your carb's just not right. Yet      

     

[Mac350]

I put the new carb on after checking and cleaning it. I found 2 things better on the new one, the seal around the float bowl on the old was very flat and looks like someone tried to use a sealing paste to bodge it, I assumed it would only be an issue of leaking fuel out which it wasn't doing so ignored it before, but maybe it sucks air in? The other thing was the slide was smoother and more responsive on the new one. The older one might even be sticking a bit before coming back down.

Put it on and it started ok but then was missing quite badly. When it misfired at slow revs in neutral there was an ugly sounding clonking from in the engine each time, i hope this is normal and just where tension is coming off a part which then catches up and hits it when it fires next. Not a good thing I imagine but hopefully not a problem? I didn't notice this at any setting with the old carb though.

I turned the idle mix screw out and got it ticking over ok, took it for a ride and it was backfiring a bit on the overrun, I adjusted the mix screw out a few more times and that was cured. It feels like if it was just for around town i'd be happy with it, it takes off from the lights and accelerates through the gears with WOT about as fast as i'd expect any heavyish 350 to. (don't worry I won't always be riding like that)

But it still feels like it hesitates at times even on the flat. I then went up a long dual carriageway hill and found it lacking. Much better than it was before when I feared I wouldn't get up doing 20mph but rather than just being a bit slow it was missing/hesitating. It seemed to do better going up to a higher gear and winding on than trying to rev out in a lower gear but was choppy and hesitating in either. At the top i checked the temp and was ok under 150 oC at plug and colour of plug seemed lean if anything. The plug is so new there was hardly anything on it to show a colour. When I got home I checked again it seemed greyish if anything on a little patch of deposit, certainly not oiled up rich but maybe showing lean, that was after cruising home. I checked the compression and it was a little over 150 PSI when hot. It still starts easily hot or cold still. I don't even need to find TDC etc when hot, as long as its not just before TDC I can just kick from sitting and its running.

Its still not right and I don't feel like its ready for a long ride out but glad to say its much better.

I've a cone filter on the way which will make taking the carb on and off easier. But maybe make it more lean when it seems likely leanness is the issue isnt it?

Any suggestions on what I should try diagnostically to get this tuned in further?

I think its about time I did a full fluid change which will let me inspect things as well. If anything the oil seems always a little high on the dipstick, not sure if you measure with it screwed back in or just placed back after unscrewing?

There is a rattle from inside my tailpipe, i'm feeling like taking the whole exhaust off anyway for a look. It sounds unrestricted but I don't really know whats what with it. I noticed in the owners manual in the exhaust servicing section a sentence starts "take a potato..." to stuff the exhaust before pouring a caustic cleaner in. I wonder if Halfords sell them 

[Mac350]

     All this seems to me to point to incorrect Pilot Jet.

      I'm not familiar with the carb you have, but the engine should idle correctly with the mixture screw (whether it's an Air or a Fuel Screw) screwed Out 1 & a 1/2 turns from gently bottomed out. And if the pilot is correct, you should be able to blip the throttle without it dying. THEN work on needle height.

     You've gotta work step by step, last being Main Jet, One thing at a time.

      I've had the feeling all along in your story, that your carb's just not right. Yet      

Yes the needle height next. Will wait until the new air filter arrives

[Mac350]

So I've just been porting the head best I can. Inlet side I removed the big lip towards the valve end so its a nice smooth port and sanded the port for a better finish. Exhaust end I removed more, taking out to the diameter of the gasket all around where before it was all out on one side with a large chunk bigger than the gasket on the other. Its about 28mm diameter now, I've burred out a little of the front aperture of the exhaust which had an inwards bur, so that is also about 28mm but narrows slightly at that neck and the end of the down pipe shows its the lined one but the bore is anyway about 28mm. I've removed the baffle from the tailpipe so its all straight through.

So would this be considered still a restrictive exhaust? Does it make that much difference if the gases can expand just out of the head in the header pipe or is a parallel straight through enough?

[Mac350]

I've beveled the front end out to the same diameter as the gasket which must be better but it still restricts down from 30 to 25mm, 78mm2 from a possible 94mm2 so I could have another 20% through flow for the price of an exhaust that is 30mm all the way. Does that have an easy to calculate relationship to HP?



The diameter of the carb is currently 26mm so at least it is balanced as it is, not sure how the match matters though as combustion has been added to the equation after the carb but still only a certain amount of air can come through. Would a bigger exhaust allowing quicker clearing compress the air as it draws more through a smaller carb? 

[AzCal Retred]

I'm really feeling liberated by the feeling that there is nothing wrong with modifying these bikes.
Mac350 - It's great to see you jumping in and getting so much pleasure out of "fettling" this machine. It's great fun removing the lumps & warts and seeing the little performance gains. Big pieces that move real slow make for accessible technology!

Does that have an easy to calculate relationship to HP?
Nothing is ever that simple. Wave action has a lot more to do with exhaust scavenging. Every section change creates a reflection wave. Smoothing off that ledge cleans up the resonant path. Ideally there will be a negative pressure wave sitting in the exhaust port when the exhaust valve cracks open, evacuating the cylinder so that when the intake opens there will be a partial vacuum setting in there, allowing in more fresh charge. Big picture, tuned overall internal length determines the RPM range the exhaust scavenging effect happens at, longer is good for lower RPM. If it was just driven by "back pressure" from pipe diameter restriction we could get max power by removing the pipe entirely. Proper scavenging from tuned length increases mass flow thru the system and increases power output. It's a black art! 

[Mac350]

Wave action has a lot more to do with exhaust scavenging. Every section change creates a reflection wave. Smoothing off that ledge cleans up the resonant path. Ideally there will be a negative pressure wave sitting in the exhaust port when the exhaust valve cracks open, evacuating the cylinder so that when the intake opens there will be a partial vacuum setting in there, allowing in more fresh charge. Big picture, tuned overall internal length determines the RPM range the exhaust scavenging effect happens at, longer is good for lower RPM. If it was just driven by "back pressure" from pipe diameter restriction we could get max power by removing the pipe entirely. Proper scavenging from tuned length increases mass flow thru the system and increases power output. It's a black art! 

I remember a school friends old C90 that we used to hack around his large back garden and one day the manifold broke off and it ran terrible with no exhaust. That was the first time I heard mention of back pressure! And today is the first time hearing of scavenging.

Just looking it up more and I'm reading and I think understanding so far put simply there is exhaust gas moving out of the cylinder plus a faster pressure wave which presumably hits the gas in front from the previous combustion causing that to accelerate which further reduces the pressure in the area behind it which pulls the following expelled gases and so on.

So as long as the pipe is long enough for multiple waves to be within it there will be an increased vacuum effect caused by the pressure waves. Presumably then for high revving it can get away with a shorter pipe and low revving could do with longer. But then not so long that the gases aren't moving under their own steam before they exit. If they have to be pushed presumably that will mess things up further back.

Narrower pipe said to be better for low RPM. Makes sense as in a wider empty pipe the pressure wave won't have such an impact on less densely packed gases. Presumably that's where "back pressure" term comes from though I noticed some people sort of debunking that its even a thing. Maybe should be said as "Something dense for the pressure wave to hit."

I saw something about a pressure wave "rarefracting" from the exit of the pipe back to the valve but it made no sense and seemed unnecessary so i'll discount it unless someone says its legit.

Any restriction will slow down the pressure wave which will reduce the negative pressure in the area behind it that is pulling the next wave so mufflers and sharp kinks = bad.

Header design to factor in scavenging seems mostly related to multi-cylinder headers replacing a basic all in one manifold which makes sense. Not such a worry for our singles.

From what I can gather it seems a certainty that having a restriction from 30mm manifold to 25mm front section followed by a 30mm pipe will be bad in either low or high RPM. Seems that having a straight through smooth pipe with no disturbance is ideal. How mine was from the factory would have been about 20mm bearing in mind that the pipe couldn't align properly with the misaligned hole in the port. Bizarre to think it must have been a replicated error for as many heads that were made from that mould and presumably the moulds are made from moulds...

Seems like we don't need to worry about having a too big pipe for low range power, all the exhaust calculators online I tried think we need about a 2" exhaust pipe! So I'll be on the phone to Hitchcock's tomorrow then unless there are other options for buying an unrestricted header I should consider?

[Mac350]

You know how fresh eyes can sometimes be useful. Is a lot of whats talked about exhausts claptrap? This all sounds like junk physics - https://www.cycleworld.com/everything-youve-ever-wanted-to-know-about-motorcycle-exhaust/ "That negative wave enters the cylinder, at first extracting inert exhaust gas from the combustion chamber above the piston, then entering the intake system to cause intake flow to begin entering the cylinder even before the piston has started to move down on its intake stroke."

what is a negative pressure wave that can enter things?? Like a moving black hole? Can't he just say the gases moving away and the valve shutting behind it created negative pressure otherwise known as a vacuum and that will suck air through if it can when the valves are at overlap.

A state would exist if the vacuum's negative pressure is not equalised by gases coming through from the engine where some gases will be drawn back from down the exhaust once the forward momentum is less than the negative pressure of the vacuum. That could create a bit of back flow *of particles* but thats not at all "a negative pressure wave"

This person https://burnsstainless.com/blogs/articles-1/exhaust-header-theory says a rarefaction wave travels the whole length of the exhaust pipe only as the pressure wave exits. Its just not how it works. Handy diagram here. https://en.wikipedia.org/wiki/Rarefaction The pressure compresses and decompresses as it travels  He seems to then mix up that wave aspect with particle back flow that could happen to fill the vacuum.

A pressure wave (a wave of negative-ness no less) won't bounce back off an open end of a pipe where the pressure is released and all the way back up the pipe against the flow and into the cylinder to extract things. BBB

[Mac350]

I've just thought of how to convince anyone the rarefaction going back to the cylinder idea is nonsense. Because you might be thinking "But what if the pressure wave moves so fast it exits the end of the exhaust before it has decompressed the bit behind it, isn't there a vacuum (of sorts/equilibrium) from the pressure wave to be back filled?"

Keep in mind the gases coming from the engine are a fluid flowing down a pipe. The pressure wave exits the cylinder faster than the gases and travels down the pipe through whatever is already there ahead of it while the gases from the same combustion follow behind.

A pressure wave moving through a fluid compresses the particles as it barges through them and as they are squeezed just ahead they are therefore a lower density/compression just behind (rarefaction), both sides are released once the wave has passed through, that releasing includes some particles going back away from the wave until they are are all back into their previous resting state.

The key thing to bare in mind is the only particles that will be released and can travel back upstream are the ones it has already compressed IE the ones the wave has moved through which were ahead of it when it left the cylinder. No matter how slowly the gases were moving, if they were flowing down the pipe at all then it is impossible for the release to be in particles at the cylinder at the time when the pressure wave exits the exhaust. It can't act on particles that came out of the cylinder behind the pressure wave or since. Only the ones it has passed through.

the pressure wave could bounce off a surface and move in another direction but that is something separate.

[Mac350]

Curiosity won and I tried to get the barrel off. Undid the nut, couldn't get the barrel to budge. Tried going around it with a leather faced hammer as much as i dared but gave up. The 5 through studs all move a tad when pushed so its just the gasket baked on. The 2 stud holes nearest the push rod tube are full of oil which seeped up.

I measured the bore in place and widest I found was 70.081mm against a 70.15 service limit. I only have telescoping bore gauges so not the most accurate way but got pretty consistent results in 5 places I measured. The top part where the piston rings don't touch was 69.896mm. There was a just discernable sideways movement of the piston but I have to assume its within the 0.3mm limit as i can't measure the piston.

If there is a trick to getting the barrel off please let me know!

I'd like to have a nice shiny piston top but I don't like the idea of brushing it off into the gap above the piston rings which seems inevitable if i do it in place... It seems like the least harm would be leaving it as it is

[Adrian II]

How about a little smear of grease around the edge of the crown with the piston at TDC, while you use a flat scraper to get the carbon off? Wipe clean, then rotate the engine a few degrees to mop up any residue off the top of the bore. Or soak the piston top in Redex.

To avoid the risk of damaging what sounds like an OK set of piston rings, I would leave the barrel on, but if it does need to come off, you might need to slacken off the top two crankcase studs nearest the crankcase mouth, but giving the cylinder base flange a good seeing to with a hot air gun or carefully applied blowlamp ought to be enough to soften any gasket goo. I don't think the factory used green Hermetite.

A.

[Raymond]

If you decide to remove the barrel. Yes to loosening the two crankcase studs that run near the barrel mouth. After that, and checking the nut above the tappet cover was removed, had to use a piece of wood and gentle taps against the barrel & lowest fin to get it to move. As soon as there was slight movement, it was wiggling the casting to and fro till it was happy to lift up, up and away. Catch the piston & rod as they come free.

[Mac350]

thanks for the ideas but yes will leave it in place for now. It does seem like everything has had only minimal wear so far so will just clean and put back together.

[Mac350]

How about a little smear of grease around the edge of the crown with the piston at TDC, while you use a flat scraper to get the carbon off? Wipe clean, then rotate the engine a few degrees to mop up any residue off the top of the bore.

that sounds like a very workable plan thanks.

[Mac350]

Happy days over here. I'm converting an extension into a workshop partly inspired or at least sped on by having this bike. Took the bowed and damaged chip board floor up expecting dirt same as rest of the house, but revealed an already concreted floor! Just need to grind it flat and paint it with something oil proof.

[tooseevee]

If you decide to remove the barrel. Yes to loosening the two crankcase studs that run near the barrel mouth. After that, and checking the nut above the tappet cover was removed, had to use a piece of wood and gentle taps against the barrel & lowest fin to get it to move. As soon as there was slight movement, it was wiggling the casting to and fro till it was happy to lift up, up and away. Catch the piston & rod as they come free.

     I remember when I had my barrel off I hammered & hammered (worrying about breaking a fin) until I got sick of it & my hands were killing me. So the next day I did what I did on the head. Sat & tapped a thin putty knife round & round into the gasket until it finally freed.

     The engine had Very low mileage at that time (2014) & I don't know what kind of cement they used, but it certainly worked. Spent hours cleaning those gaskets off with various chemistry experiments & careful scraping.   

[Mac350]

     I remember when I had my barrel off I hammered & hammered (worrying about breaking a fin) until I got sick of it & my hands were killing me. So the next day I did what I did on the head. Sat & tapped a thin putty knife round & round into the gasket until it finally freed.

     The engine had Very low mileage at that time (2014) & I don't know what kind of cement they used, but it certainly worked. Spent hours cleaning those gaskets off with various chemistry experiments & careful scraping.

I'm glad I didn't manage now, scrapping the gasket off worrying about bits falling into the crankcase or damaging the face, not much fun. I've got an old can of gasket remover spray but I remember it not doing much when it was new. Did you find anything helpful other than scrapping?

[tooseevee]

I'm glad I didn't manage now, scrapping the gasket off worrying about bits falling into the crankcase or damaging the face, not much fun. I've got an old can of gasket remover spray but I remember it not doing much when it was new. Did you find anything helpful other than scrapping?

    I used everything from acetone to gasoline & kerosene. Let it sit overnight. Mostly careful diligence to not gouging. Used putty knife & old wood chisel then emery cloth. Mostly I remember my hands hurting. I used grease only on the base & head gaskets & RTV around the push rod holes.

    No oil weeps later, but very low mileage. Never ever got near the 500 mile retorque.