[Mac350]

My bike is 20 years old, last 10 years sat mostly still, 8000 miles total. As the head is coming off and I'm going to take the valves apart to inspect I figure I'd be daft not to just buy some new springs. I see individual springs on Hitchcocks for £6 and a kit for £30 with no details of what else is in it but presumably other parts that I might as well change. I've also seen some talk of upgrade spring kits but not sure if it applies to the lean burn engines or what the advantage is or where to get them. Any tips would be welcome! 

I've been reading up on valves and springs and adjustment so now I feel like I want it to be just right https://mooregoodink.com/valve-springs-valve-clearance-bounce-float-and-surge-a-few-helpful-details/

[AzCal Retred]

Others will chime in here, but the lightest springs you can get away with are generally the easiest on the valves & cams. Low RPM use isn't very demanding. When you spin up the engine you'll need enough spring to keep the lifter following the cam profile faithfully. Springs can also lose tension & get "weedy" and sack. Usually the decompressed height will indicate if they are "sacked out".

[Mac350]

Others will chime in here, but the lightest springs you can get away with are generally the easiest on the valves & cams. Low RPM use isn't very demanding. When you spin up the engine you'll need enough spring to keep the lifter following the cam profile faithfully. Springs can also lose tension & get "weedy" and sack. Usually the decompressed height will indicate if they are "sacked out".

I'll measure against the specs when I remove them but even if they are the normal height just being 20 years old seems enough reason to get new for the price of them.

In case it helps with a recommendation I realised I haven't quite given up wanting to ride fast so will be wringing more out of it than I probably should. I better have the performance end of things. This sounds good https://accessories.hitchcocksmotorcycles.com/18471 I guess I'm wondering if there is an AVL version, as well as just spring recommendation if not

[Mac350]

This old thread ended prematurely after making a worrying prediction of doom for me occasionally at WOT on my AVL https://forum.classicmotorworks.com/index.php?topic=18587

Is this born out by many failures?

Either way I need to confirm what cams it has and make 100% sure the springs are up for it.

[SteveThackery]

Stronger springs than stock won't - in themselves - improve the power output at all.

However, if you've got a more radical cam profile, and/or you intend to raise the redline, then stronger springs are worth buying.

That "performance" valve kit won't make any detectable difference unless you go for hotter cams as well.

Of all the tuning changes you can make to a bike, a hotter cam is by far the most effective. So if you really do want a power boost then the cams and valve kit combined would be the way to go.

[Mac350]

Stronger springs than stock won't - in themselves - improve the power output at all.

However, if you've got a more radical cam profile, and/or you intend to raise the redline, then stronger springs are worth buying.

That "performance" valve kit won't make any detectable difference unless you go for hotter cams as well.

Of all the tuning changes you can make to a bike, a hotter cam is by far the most effective. So if you really do want a power boost then the cams and valve kit combined would be the way to go.

Time permitting I'll take the cover off and check what cams I've got tomorrow.

[allanfox]

I have tried some 'S' cams and did get improved mid range power, would pick up really cleanly powering out of a corner. But they were very noisey, they were old and might have been worn a bit, the noise was from the follower losing contact with the cam after it has gone over the top, very steep angle so shuts with a clonk. So I think stronger springs would be beneficial for keeping the follower in close contact and less noise, I think/hope!

I would up fitting a set of low mileage cams (retarded a tooth on inlet) from a stock iron barrel engine (with H's adjuster extenders as the pitch circle is smaller) , a huge difference and it runs really well with them in and with stock AVL springs, a cheap fix and it goes like a rocket, had over an indicated 100 MPH a couple of times without issues to date. Also fitted with an EFI piston with a slight reduction in compression.

[mcplorer]

I would up fitting a set of low mileage cams (retarded a tooth on inlet) from a stock iron barrel engine (with H's adjuster extenders as the pitch circle is smaller) , a huge difference and it runs really well with them in and with stock AVL springs, a cheap fix and it goes like a rocket, had over an indicated 100 MPH a couple of times without issues to date. Also fitted with an EFI piston with a slight reduction in compression.

Is that cam from Iron Barrel Bullet 350 or 500 (or both use same cams?).
Are those cams direct fit on a UCE Bullet? And how those cams makes the engine rev more? What's special about the Iron barrel Bullet cams? Also when we say cams from Iron barrel do we talk about changing inlet and exhaust both cams as a set or just the inlet cam?
I know I asked quite a few questions but then that's why we have this forum, to help each other 

[Mac350]

I'm curious why the CI bullet cams are hotter than the more powerful AVL. I'm guessing the AVL was built for economy end emissions and as it was already faster than the CI they didn't feel the need for more from the cams? I should have time for a look what cams I have tomorrow with any luck.

[Adrian II]

Is that cam from Iron Barrel Bullet 350 or 500 (or both use same cams?).
Are those cams direct fit on a UCE Bullet? And how those cams makes the engine rev more? What's special about the Iron barrel Bullet cams? Also when we say cams from Iron barrel do we talk about changing inlet and exhaust both cams as a set or just the inlet cam?
I know I asked quite a few questions but then that's why we have this forum, to help each other 

AFAIK the UCE/EFI cams have 36 teeth on their gear wheels, but the AVL and iron barrel cams definitely have 40 teeth on their gearwheels. The UCE/EFI crankshaft also has an integral timing pinion machined into it, not like the separate one on the the IB and AVL, so you can't just retro-fit a whole camshaft set.

I'm curious why the CI bullet cams are hotter than the more powerful AVL. I'm guessing the AVL was built for economy end emissions and as it was already faster than the CI they didn't feel the need for more from the cams? I should have time for a look what cams I have tomorrow with any luck.

I think there's some voodoo going on with the valve train geometry here, possibly the rocker ratio, which unintentionally works in favour of at least the 500 AVL if you fit a set of original Redditch "S" cams, some Indian IB cams CAN work very well in an AVL too, though I gather varying levels of accuracy in the old IB cam production meant timing could actually vary from bike to bike, with some performing better than others. I wonder if any Chennai Bullets were quite unintentionally given a set of Redditch "R" profile cams without the owner (or the factory) realising.

A.

[mcplorer]

AFAIK the UCE/EFI cams have 36 teeth on their gear wheels, but the AVL and iron barrel cams definitely have 40 teeth on their gearwheels. The UCE/EFI crankshaft also has an integral timing pinion machined into it, not like the separate one on the the IB and AVL, so you can't just retro-fit a whole camshaft set.

I think there's some voodoo going on with the valve train geometry here, possibly the rocker ratio, which unintentionally works in favour of at least the 500 AVL if you fit a set of original Redditch "S" cams, some Indian IB cams CAN work very well in an AVL too, though I gather varying levels of accuracy in the old IB cam production meant timing could actually vary from bike to bike, with some performing better than others. I wonder if any Chennai Bullets were quite unintentionally given a set of Redditch "R" profile cams without the owner (or the factory) realising.

A.

@Adrian II

UCE 500/350 both has similar cams and inlet is 38 teeth (I will verify again though)

Thanks for clearing the air on IB cam on why it can't be used in an UCE.

Extremely noob question: when we talk about high lift cams or performance cams be it custom made or IB cam then do talk about only inlet cam or inlet and exhaust both? Do we change both the cams or on most of the instances it's just inlet which will do the job?

[Mac350]

So my cams have 3L1 stamped on the exhaust cam and 4A1 on the inlet. Base diameter is 1.219" and the lobes are 1.509" both within a thou of each other and looking in good condition. Any idea which cams they are?

[Mac350]

That spare engine I bought from Hitchcocks either has the wrong (longer) spark plug in it or its a 500. Any way to tell other than taking the head off? I can't see any markings on the barrel. It looks in good condition and apparently was a reliably sourced runner from India so I don't want to take it apart just to find out.

[Adrian II]

The 500 will have a tapered drive side alternator shaft for the TCI alternator. IIRC yours is the CDI crank which was never fitted to the 500.

Well, I say "never", I actually have a set of 500 Electra-X crankcases with a rebuilt 350 AVL crankshaft in it, allegedly rebalanced for the 500 Electra-X piston... I know someone in Australia who is also building a 500 AVL hybrid in Bullet crankcases with a modified 350 AVL crankshaft. It's quite unlikely that yours is any different from how it left the factory, however.

Can you post a picture of your cams, or do they look like these lean burn items?

https://accessories.hitchcocksmotorcycles.com/9851?qty=1&continue_url=https%3A%2F%2Fwww.hitchcocksmotorcycles.com%2Fpartsbook-pages%2F6057

https://accessories.hitchcocksmotorcycles.com/9852?qty=1&continue_url=https%3A%2F%2Fwww.hitchcocksmotorcycles.com%2Fpartsbook-pages%2F6057

A.

[Mac350]

The shaft is parallel. I'm surprised its not marked anywhere on the engine

[Mac350]

Was I expecting a completely flat piston??



The head seems flat, the little bit of blue you can see is all that was left after a couple of spins on some 2000 grit wet and dry. The old scouring marks look like someone went at it with 60 grit but it seems not to have left much in the way valleys as the blue came straight off. Some Wellseal with do it ok?



Do you think it was leaking just because the gasket went on without using any gasket compound? Maybe they didn't torque it back down after 500 miles? Not even sure it has done 500 since it was changed tbh but it was only doing a hundred miles a year for the last decade so it could have been a while ago.




The exhaust valve was fairly well blacked but don't know what is normal or how many miles this looks like. Its bathing in seafoam overnight to see how good that stuff really is



This mystery washer was down in the tappet cover next to the push rod.



I checked the parts against the limits given in the service guide that came with the bike. I've not seen the specs for the 350 AVL anywhere else so will give it in case anyone from the future needs it. Valve springs are given as New minimum 42.80mm, New max 44.80 and service limit 41.50mm. Mine measured 44.00mm and 44.10mm so well within limits but would I be able to know which springs they are? Given they are the length they are does it seem pointless getting new? Does it seem likely they have been under compression for 20 years anyway. Maybe they are recent already.

The only thing out of spec were the push tubes both have 0.09mm run out against a service limit of 0.05m. Worth getting new? £36ish from hitchcocks.

Overall I'm pleased with all of it, came apart easily, oil seems to be everywhere it should be and nothing seems worn.

[Adrian II]

Yes to flat topped pistons. IIRC the UCE/EFI are dished.

The mystery washer is actually a spring washer, it fits between the rocker and the cylinder head casting where the rocket shaft slides in (at the oil feed end). Should be one on each rocker, they're a bit fiddly to get in, so I can see why one wasn't properly fitted.

Ref the state of the cylinder head joint face, I once bought a brand hew Electra-X cylinder head from Watsonian-Squire to find what I can only describe as a wavy finish at the joint face, something wrong with the milling machine set up! Cured it by rubbing down on 120 grade wet and dry on a piece of plate glass, can't remember if I switched to a finer grade to finish, but 360 would do. Yes, new gasket and Wellseal.

Somewhere at the top of the AVL section there is a link to download the "retired models" parts book from 2013, this will have all the 350 Machismo and Thunderbird part numbers listed, feeding said part numbers into the search button on Hitchcocks' web site (and/oreBay) sometimes yields results.

Your cams are the same as the Electra-X cams, so AVL.

A.

A.

[Mac350]

So i bent my new valve spring compressor so it doesn't fit back in the box. Trouble was getting the initial movement no doubt you know the thing. But I didn't use other than hand pressure on the screw so I assumed it was just junk so will return it and find a better one. But looking for a good older one i came across this chunky looking one with this warning



Was wondering how do I break the seal on the cotters before using it?? Found a video of someone whacking it with a socket and the cotters just came out. Then found this video slightly finessed version. Any good for our bikes?

https://www.youtube.com/watch?v=qEe8C5u1LWg

[Paul W]

I think they mean that a percussion persuasion instrument should be used to “break the seal”. Fit the valve spring compressor, tighten it up a little to put the spring cap under pressure and tap the end until the cap pops loose.

[Mac350]

I think they mean that a percussion persuasion instrument should be used to “break the seal”. Fit the valve spring compressor, tighten it up a little to put the spring cap under pressure and tap the end until the cap pops loose.

I'd spent a bit extra and bought the Laser solid metal bar compressor kit having noticed its what Hitchcocks sell, rather than the £15 welded tube type but if that still isn't enough I might as well use a socket to hit it or do this https://www.youtube.com/watch?v=S8E8T8Ja0fY and buy the cheapest kit I can find to install them. Just looking at the reviews on Amazon and sure enough its split between people who don't know to hit them giving one stars because it bent and people who either know or they were lucky giving the tool 5 stars.

[Mac350]

Yes to flat topped pistons. IIRC the UCE/EFI are dished.

Your cams are the same as the Electra-X cams, so AVL.

Electra-x is a 500cc? Was it right all the uk sold AVLs were 500?

Its all a bit boring then, regular cams, regular piston. I might as well carry on with what it is, get it running right before worrying about exotic cams. Or i'll not appreciate the difference.

[tooseevee]

So i bent my new valve spring compressor so it doesn't fit back in the box.

   Your new (old) one's a Sheffield  I don't think you'll bend that one 

    You gotta "tap 'em" a bit. It's sorta like having to hit a mule in the head to get its attention 

[Mac350]

   Your new (old) one's a Sheffield  I don't think you'll bend that one 

yes thats what I was thinking get an older proper one usually works out best. In the end though China won for an unbeatable £8 delivered with some discount codes. Once I realised I have to hit it anyway and after that people are pressing them in by hand I figured it can't have to be that strong once over that initial hump

 

  You gotta "tap 'em" a bit. It's sorta like having to hit a mule in the head to get its attention 

sounds dangerous!

[Mac350]

By the way as i mentioned it just to note the seafoam soak did absolutely sweet FA. I've been using it to try to clear my injectors on my 160k miles diesel and it seems to have helped but i'm pretty sure it is just 1% better than nothing so takes me back to just before failure again, but as it seems to do something people keep buying it and the engine keeps running in a poor state just the right side of a failure. The injectors should be pulled and properly serviced and will then maybe do another 160k. As the old saying goes if it sounds to good to be true it probably is!

[Adrian II]

Don't know what's in the Seafoam product, I think most carb cleaning fluids are toluene based.

Yes, the Electra-X is a 500, it's the only AVL model our importers at the time thought we should have (sold between 2004 and 2008), even though the A350 Machismo had been on the Indian market since 1999. So any of those such as yours + 350 Thunderbirds + maybe a couple of A500 Machismos that you might actually come across over here will all have been private imports.

A.

[Mac350]

Yes to flat topped pistons.

Should i be worried about changing cams to any available causing contact with the flat piston? I notice other pistons are indented to accommodate the valves

[Adrian II]

It is something you would have to watch out for, particularly if you're timing the cams on the factory timing marks instead of retarding the inlet by one tooth. Most likely the inlet valve head would just carve itself a small ding in the crown in the 8 o'clock position, though you would definitely hear a "clonk" as soon as the two met. Have managed to do this myself  ,   but have also come across the same thing in a used 500 AVL engine I bought. Not what you want.

You can either retard the inlet cam one tooth so that the piston crown has been and gone by the time the valve head gets there, or you can cut/grind/Dremel your own valve pocket to suit. One of our forum members in France has done for his CGT535, though you'll see he had to make a pocket for the exhaust valve too (which you most likely wouldn't have to), as he was using high lift cams AND a shortened cylinder barrel.



Picture: Taurim

[axman88]

Don't know what's in the Seafoam product, I think most carb cleaning fluids are toluene based.

Assuming we are talking about their "Motor Treatment" product, the folks at Sea Foam Sales tell us, via the published SDS, that it's a mix of petroleum distillate and isopropyl alcohol, but they don't reveal the exact recipe.  https://seafoamworks.com/wp-content/uploads/public/resource-library/2021/08/SFMT-SDS-US-ENG-v20191016.pdf

It appears that a previous SDS (circa 2015), may have stated:
CAS # Wt.%
Pale Oil 64742-54-7 40.00 - 60.00 N/Av >15000 mg/kg >5000 mg/kg
Naphtha 64742-49-0 25.00 - 35.00 N/Av >5000 mg/kg N/Av
IPA 67-63-0 10.00 - 20.00 17000ppm 4720mg/kg 12890mg/kg

But, this has understandably been made less scrutable.

The internet says that a good homebrew recipe is:
   ~2 parts Diesel fuel
   ~2 parts Naptha
   ~1 parts Isopropyl

This guy went through some considerable experimental efforts to match appearance, specific gravity, and viscosity.  https://hildstrom.com/projects/2010/01/seafoam/index.html#:~:text=This%20DIY%20homebrew%20solution%20has,3.5%20oz%2091%25%20isopropyl%20alcohol.

Quantifying efficacy would be another matter entirely.