[ivantheterrible]

my decompressor seems to be nonfunctioning. I can barely move the switch at the handlebars, though the cable doesn't seem to be kinked and it seems well routed. I press it at the cylinder head and it doesn't seem to move much, though I'm not sure it's supposed to.


When I bought the bike the seller said he experienced a loss of power and thought it was the head gasket. I take everything he said with a grain of salt, as it was his first motorcycle. With that said, it doesn't seem to have the compression I thought it would. I can freely kick it with hardly any resistance (I can even operate the kicker with my hand.) From the videos I've see, I should be able to stand on the kicker with the decompression off.

I've removed the cable, so there's no way the decompressor could be working, correct? Also, this bike has the 612 kit, so it should have higher compression, right? so harder to kick? What's the easiest way to test if it's a blown head gasket or bad piston vs something wrong with the decompressor?

I'm trying to do some reading on this, but I hope it's not a bother to start a new thread so I can ask specific questions.

[ace.cafe]

It can be assembled wrong. I suggest looking at exploded diagrams, and also at close-up photos.

Be aware that pulling the pin can result in the decomp valve dropping into the cylinder, requiring head removal to retrieve it.

[Adrian II]

You're probably better off using an old-style classic Brit bike handlebar decompressor lever once the valve is set correctly and working properly, eg this one, ebay item 263924893802.



A.

[ivantheterrible]

I'd like to do away with the decompressor cable altogether. I read that some have fit a Harley Davidson decompressor at the cylinder head. Any feedback on this would be appreciated.

[ivantheterrible]

ok, now I'm getting paranoid that I might have screwed the pooch with the decomp removal. I removed the cable before I removed the decompressor from the cylinder head. I just read that the cable must remain attached or else the valve will drop into the cylinder. I knew that the decomp had to be taken out of the head before disassembly, but I didn't know this meant not removing the cable. With that said....it looks like the valve is still attached.

[Seipgam]

No problem with removing the cable, just don't remove the little split pin while the unit is still in the head because as Ace noted the valve stem itself is likely to drop inside.
Remove the unit from the head then you can do what you like.

Geoff.

[ivantheterrible]

thanks! puts my mind at ease.

[ace.cafe]

I'd like to do away with the decompressor cable altogether. I read that some have fit a Harley Davidson decompressor at the cylinder head. Any feedback on this would be appreciated.

You can eliminate the cable, and still use the OEM decompressor manually..
We have done plenty of miniature Harley aftermarket type decompressors, but it requires machine work. It is not a drop in mod.

[ivantheterrible]

thanks ace, good to know. when i press it in (decompress, correct?) does it stay in on it's own, or do i hold it and operate the kick while holding?

[ivantheterrible]

out of curiosity....can you use the decomp hole for a compression test?

[ace.cafe]

thanks ace, good to know. when i press it in (decompress, correct?) does it stay in on it's own, or do i hold it and operate the kick while holding?

You use the kick start pedal to bring the piston to the place on the compression stroke where you feel compression resistance at the kick start pedal.
Then, push in the decomp to release pressure and hold it down while you SLOWLY and GENTLY move the kick start pedal to bring the piston up to TDC. You can determine the correct position by watching the ammeter deflection to indicate that the points have opened.
Let off the decompressor so that it returns to the closed position.
Then, let the kick start return spring bring the kick start pedal all the way to the top. Get a good strong position to kick, and kick it once good and hard, and follow thru all the way to the bottom.
If that doesn't start it, repeat the procedure.

If it takes more than 5 kick attempts, then investigate what is wrong. Don't wear your leg out trying to kick start a bike that isn't going to start.

[ace.cafe]

out of curiosity....can you use the decomp hole for a compression test?

Theoretically you might be able to, if the gauge fits into that hole.
However, you need to make sure that the spark plug won't spark during the test.

As a rule, it is normal procedure to remove the spark plug and use that hole, so that prevents a spark from happening. I strongly recommend removing the spark plug and using that hole for the compression test, as intended.

[ivantheterrible]

will do, thanks!

[Bilgemaster]

Vanya (that's the common Russian nickname for Ivan): I don't know why one would want to check compression at the decompression valve orifice, but I guess one could with a good enough seal there. Definitely pull off the spark plug cap first!

More to the point, I would sooner expect some misassembly or maladjustment in the decompression valve assembly or some problem with the lever or cable. I also have a 2005 Military. I don't have the fancy piston rigamarole, but my decompression gear is bone stock and functions flawlessly.

Would it help you to view a film of its proper operation, with maybe a few detailed shots showing how it OUGHT to look? Well then, welcome to the world premiere Royal Command Performance of the soon-to-be classic Avant Garage short film, Decompressor Operation Thrills for Dirty Uncle Vanya.

And here are those workout stills for the gals...

First relax...

And then compress...

Let those compressed hydrocarbons flow!...Now gimme 12 good reps!

[ivantheterrible]

entertaining as well as informative, as always!

[ivantheterrible]

You use the kick start pedal to bring the piston to the place on the compression stroke where you feel compression resistance at the kick start pedal.
Then, push in the decomp to release pressure and hold it down while you SLOWLY and GENTLY move the kick start pedal to bring the piston up to TDC. You can determine the correct position by watching the ammeter deflection to indicate that the points have opened.
Let off the decompressor so that it returns to the closed position.
Then, let the kick start return spring bring the kick start pedal all the way to the top. Get a good strong position to kick, and kick it once good and hard, and follow thru all the way to the bottom.
If that doesn't start it, repeat the procedure.

does the ammeter trick work with electronic ignition? Mine doesn't seem to deflect, or move much at all.


If it takes more than 5 kick attempts, then investigate what is wrong. Don't wear your leg out trying to kick start a bike that isn't going to start.

[ace.cafe]

If your ammeter doesn't move, listen for the sound of the air going out the exhaust pipe to stop.
You will get a feel for how far to move the pedal after doing it a few times. It isn't super critical. Just get it up around TDC or a little after, and then kick.

[Bilgemaster]

If your ammeter doesn't move, listen for the sound of the air going out the exhaust pipe to stop.
You will get a feel for how far to move the pedal after doing it a few times. It isn't super critical. Just get it up around TDC or a little after, and then kick.

Thanks for the kudos! Just to add my two kopecks to Ace's explanation, the little ammeter swing he describes, and which is also explained in countless "How to Start a Royal Enfield Bullet" checklists and also YouTube videos, is caused by the electrical draw of the ignition points closing and opening. Mine was fitted with an electronic ignition by a previous owner, and so does not do this little ammeter dance. I've gotta guess that with all your bike's fancy gimcracks it's even money that you may also have an electronic ignition. So don't get too hung up on the ammeter thing if nothing's going on there. Just get the kickstarter through until it's really FIRM, and then a little steady pressure until it just isn't (you don't really need a decompressor to get it there in the stroke--it just helps make it easier), and with the choke lever on the carb down, a nice solid gentle kick may get her sputtering. Mine likes the very faintest wisp of throttle when cold, but try first with no throttle at all. They flood easily. But you know, each is different. You'll get it down to second nature in no time.

One other thing: Before commencing your whole "12 Lords A'Leaping Tribute" for this holiday season, you might do well to pull in that clutch and kick it through a few times to free up those clutch plates a little to make things easier. Your right leg will thank you.

[Unlucky_soul]

You could remove the decompressor and fit in another spark plug there. Dual spark plug ignition for more responsive power and milage. Have done it on one of my bikes

[ivantheterrible]

You could remove the decompressor and fit in another spark plug there. Dual spark plug ignition for more responsive power and milage. Have done it on one of my bikes

Really?! I had no idea, that's very interesting.

[ivantheterrible]

Thanks for the kudos! Just to add my two kopecks to Ace's explanation, the little ammeter swing he describes, and which is also explained in countless "How to Start a Royal Enfield Bullet" checklists and also YouTube videos, is caused by the electrical draw of the ignition points closing and opening. Mine was fitted with an electronic ignition by a previous owner, and so does not do this little ammeter dance. I've gotta guess that with all your bike's fancy gimcracks it's even money that you may also have an electronic ignition. So don't get too hung up on the ammeter thing if nothing's going on there. Just get the kickstarter through until it's really FIRM, and then a little steady pressure until it just isn't (you don't really need a decompressor to get it there in the stroke--it just helps make it easier), and with the choke lever on the carb down, a nice solid gentle kick may get her sputtering. Mine likes the very faintest wisp of throttle when cold, but try first with no throttle at all. They flood easily. But you know, each is different. You'll get it down to second nature in no time.

One other thing: Before commencing your whole "12 Lords A'Leaping Tribute" for this holiday season, you might do well to pull in that clutch and kick it through a few times to free up those clutch plates a little to make things easier. Your right leg will thank you.

Thanks, that's helpful. Mine does have electronic ignition. I figured that the ammeter thing wouldn't work with electronic ignition.

I've had a few kick only bikes (srx600, sr500, klr250, xr650) and I had no problem with it, (this is in no way meant to be a claim of expert status) but I'll admit that I've been kicked back a couple of times on this one.
So after I hear the huff from the exhaust, that's when I'm good to kick?

[Unlucky_soul]

Really?! I had no idea, that's very interesting.

Pretty simple. you have to re-thread the decompression part to match the one in the sparkplug. then get two ignition coils... wire the second one in series i.e + from first coil goes to - of second coil.

[Bilgemaster]

[...Snip!]
So after I hear the huff from the exhaust, that's when I'm good to kick?

It's not so much a "huff" on mine, as an almost imperceptible "hiss" with decompression. (Did I miss something? Is your decompressor sorted out now?) Like I said, move the kickstart to until it's VERY FIRM...and then just a tad past that until it just softens up (with or without operation of the decompressor). Let the kickstart lever ratchet back up, and then give her the boot.

[Adrian II]

Pretty simple. you have to re-thread the decompression part to match the one in the sparkplug. then get two ignition coils... wire the second one in series i.e + from first coil goes to - of second coil.

No, the Bullet decompressor valve has the same 14mmx1.25mm thread as the spark plug, only the outer body of the plug might need to be turned down a bit to fit the outer recess in the head, and the little hole in the head that allows the decompressor to vent into the exhaust port will have to be blanked off. The normal spark plug in the iron barrel Bullet is a long-reach plug, you will need a short reach plug of the same heat value for twin plugging.

A.

[ivantheterrible]

that's all interesting, but for now, I'm just focused on riding, which I've yet to do. unfortunately, this bike is a project that is behind a few other projects. But I'm going to make it happen.

[ace.cafe]

that's all interesting, but for now, I'm just focused on riding, which I've yet to do. unfortunately, this bike is a project that is behind a few other projects. But I'm going to make it happen.

It is much easier to just leave the stock decompressor there, and just operate it however you wish.

I have done every kind of decomp mod that is possible on various Bullets, and while it doesn't do any harm, there is no measurable power gain in twin-plugging. If there is any other benefit, we haven't noticed any.

[Bilgemaster]

It just seems to me that twin-plugging gives you twice as much to go wrong.  I do admire folks coaxing every last pony out of whatever they're riding, but if I were really interested in eyeball-flattening power I wouldn't be plonking around on an old Bullet. I embrace the languid tedium. It soothes me.

[cyrusb]

Ahem, She understands it....   https://youtu.be/LD7ooOumfBM

[Bilgemaster]

Ahem, She understands it....   https://youtu.be/LD7ooOumfBM

As she rides off for the Bangalore Arm Wrestling Semi-Finals...

[Adrian II]

A 350 Electra 5S, she could just have used the electric start. Or am I missing the point? 

A.

[ivantheterrible]

got the kick down thanks to y'alls helpful suggestions. I should probably start a new thread for a new challenge, but I'll keep this here for now. Like I said the decompression/kickstarting is going well, but my new problem is the bike is hard to start, and when I do get it started, it won't run for longer than a minute or so. seems like classic carb problem, but maybe with this detail someone might point me in the right direction.....the spark plug is very wet when I check it. This is true whether I get it started with chole on or off.

[Bilgemaster]

Well, if you're getting her kicking at all that's a fine sign!

If that bike's been sitting for even a few months with fuel in its tank, then it's very possible, even likely, there's some stale fuel and its resultant ethanol snotlets causing a bit of cloggery. You could pull the carb and clean it. You might wind up doing that anyhow. But why not first try a...

Sea Foam Shock Treatment?:

• Drain the fuel tank (most easily done by pulling the fuel line off the carb, setting the petcock to 'Reserve', and observing the flow--if it's flowing freely enough that rules out any cloggery at the tank)
  
• Reconnect the fuel line and with the petcock still on 'Reserve' dump about 3/4 of a 16 oz. bottle of Sea Foam into the tank and only then top off with fresh fuel. The idea is to hopefully get a nice concentrated dose of Sea Foam into the carb bowl so it can  "marinate" a bit.
  
• Give the fuel bowl of the carb a few light taps with the handle end of a screwdriver, turn the fuel tap petcock to "Off", and come back tomorrow or the next day.
  
• It may be harder to start at first, and smoke like Hell's Barbecue Joint once it does, but this may help purge enough crudlets in the carb to let the healing begin. Use the rest of that Sea Foam at your next fill up, and all may be joy in Carbville from there on.

If I were you, I might also drop in a fresh new spark plug. I've never had much luck or use for NGKs, so I'm running a Champion N4C, which has just a tad warmer heat value than the NGK B8ES recommended in the Manual. I can't say what your fancier-pistoned ride may prefer, but the Champion's been good to me so far and looked tip-top last time I pulled it, a few months back.

If your starting/stalling woes should persist, I might urge you to film one of your semi-successful starts and just lob it up on YouTube or wherever for comment here by more practiced eyes than mine. They're likely to notice things you may not think to mention that may get your new ride quickly squared away. Posting a video is not particularly hard to do with most any phone nowadays, won't cost you a nickel, and may well save you traveling many false diagnostic paths towards dialing in your ride.

[ace.cafe]

We need to know the jet numbers that are in the carb, and what is your elevation above sea level, and average temperature range of weather you are having.

Also, if you have stock air filter and muffler, or modded.

[ivantheterrible]

I'll have a look at the jet size, but the temp was high to mid 40's, 600 feet above sea level, the air filter is one of those aftermarket metal mesh affairs, and I think the muffler is stock, but i'm not sure. I have the stock air box. Should I reinstall it?

[ace.cafe]

I'll have a look at the jet size, but the temp was high to mid 40's, 600 feet above sea level, the air filter is one of those aftermarket metal mesh affairs, and I think the muffler is stock, but i'm not sure. I have the stock air box. Should I reinstall it?

For all our purposes, your elevation is considered as sea level.
The mesh air filter is workable, but not ideal. Definitely do not reinstall the factory air filter. We should get you going okay with the mesh filter on the carb.

If you at not sure about the muffler, try to post a photo here, or look up some pictures of a stock iron barrel 500 and compare the look of the muffler. The stock muffler is a mile long. It is very restrictive. Virtually everyone puts something better on there.

Regarding the jets, it is now time to learn how to disassemble the carb for cleaning and jetting. This is a basic ownership skill, and we all learn how to do it.
You have to take off the carb, remove the slide from the body, and take off the float bowl. Jets come out with screwdriver or nutdriver. Numbers are engraved on the brass jets. There are only three jets involved. Pilot jet(small), main jet (larger), and needle jet(big and long).


Just be careful about the fuel float. Try not to bend the adjustment tab on it when doing jets. Remove the axle and treat the float carefully if you can. It works exactly like a float shutoff system in a toilet tank.

[ivantheterrible]

ok, I finally got a chance to look at it. Took the carb off, and I believe it is new, as it's very clean, and I remember that there was an invoice for a carb in the documents I got with the bike. The numbers that I could find (stamped on the brass) were 106 and 24c. Not sure which one is relevant. The muffler is stock, or it's a mile long aftermarket pipe ; )

the throttle cable seems to be messed up now. I'm guessing the cable has slipped off inside the throttle grip, but I haven't been able to get it apart yet. If anyone has any guidance, I'd take it. Otherwise, I'll see what the manual says.

[ace.cafe]

Is the carb a Mikarb?

Numbers should look like 25 on the pilot jet, and probably 110 on the main jet, and O8 on the needle jet if it is stock.

If it is an Amal carb or another type, then they have different jet numbers.

[ivantheterrible]

it's an Amal. the simplest carb I've ever seen.

[ace.cafe]

it's an Amal. the simplest carb I've ever seen.

I can't help you with an Amal.
I don't use them.
Perhaps someone else can.

[Tarnand]

The numbers that I could find (stamped on the brass) were 106 and 24c. Not sure which one is relevant. The muffler is stock, or it's a mile long aftermarket pipe ; )

106 is the size of a NEEDLE jet
24C is most likely  actually 240 and is a size of a  MAIN jet

Your carb is most likely an Amal 930 and has a non replaceable PILOT jet of size 30.
This carb is jetted for free flow exhaust and air filter.  It is not for racing but otherwise it is a really good carb.

[ivantheterrible]

thanks tarnard. Can you tell me what the plunger nob on the side is for? an enricher of sorts?

[Adrian II]

Yes, basically. It's supposed to work by temporarily flooding the carb, you press the thing down until fuel just starts to seep out, then let go.

It is not for racing but otherwise it is a really good carb.

Er, yeah...

Easy-warp flange. Quick-wear zinc throttle slide in zinc body. Fixed pilot jet can be difficult to clean out... Even Amal's successors recognized they could do better, and they came out with a version of the Mk1 Concentric called the Premier: Aluminum alloy body, hard anodized throttle slide and a proper detachable pilot jet.

http://amalcarb.co.uk/mk-i-concentric-series/900-series/base-line-specifications/30mm-bore.html

If your Amal is one of the Premier versions, relax. If not, start saving, or at least track down a heavy brass slide for it with the right cut-away. Surrey Cycles in the UK sell these.

https://surreycycles.com/product/heavy-brass-slides-for-mki-concentrics/

As an alternative there is a lot of experience with the TM32 flat slide Mikuni carb on this forum, Ace used to fit them to his Fireball Bullet conversions, though I don't know if he has worked on any iron barrel Bullets lately.

A.

[Bilgemaster]

thanks tarnard. Can you tell me what the plunger nob on the side is for? an enricher of sorts?

That's exactly right. Most folks call it a "tickler". All of my other bikes except the Bella scooter and Enfield have had Amal Concentrics, and I've always been perfectly happy with them, though they do wear quickly...especially the slides. Oddly enough, a very common "upgrade" for Nortons is to replace the stock Amals with Mikuni (of which I'm led to understand Mikarb is some sort of licensed Indian knockoff), while conversely many Enfields are "upgraded" from the often-stock Mikarb "Mikuni Clone" to an Amal. Many folks pitching their later UCE models' EFI systems in favor of good olde fashioned carburation also use Amal. In fact, Hitchcocks in England sells a whole little kit for this.

The tickler is typically only used when the engine is cold. Just press the little plunger button down until gas just squirts out the top. The Amal has a cable-operated choke, but many, myself included, never bother using it. In fact, most folks just remove its slide and such and blank off the cable's hole atop the carb with a screw. Tickling alone is enough to wake the beast from its slumbers.

There is what's known as a "tickler extension (or "conversion") kit" for the tickler button, which kind of clips in instead of the tiny original. It's not really necessary, but will help keep your finger and all future sandwiches from smelling like Hi-Test. It's a very common mod, so your carb may already have this.

This online Tuning Your Carburetor  guide should tell you more than you ever wanted to know about Amal's various offerings and their setups.

Oh yes, as 'Adrian II' has already mentioned, be very careful not to overtighten the carb to the head's manifold, as the soft flange can easily warp and bow, resulting in poor seating and air leaks. If it's handy, a little smear of red RTV gasket sealant on and around that flange's rubbery sealing ring is advisable. Harbor Freight sells a perfectly fine and inexpensive tube of the stuff. While you're at it, you'd also do well to try their No. 42 Threadlocker on those carb flange nuts--Indeed, on every nut or bolt on your Enfield that you may henceforth wrench.

[ivantheterrible]

thanks bilgemaster. For what it's worth, I just got an email from the owner who did the work on the bike, and he said the carb is a 32mm amal that came with the 612 kit from hitchcocks.

[Bilgemaster]

thanks bilgemaster. For what it's worth, I just got an email from the owner who did the work on the bike, and he said the carb is a 32mm amal that came with the 612 kit from hitchcocks.

Well, that being the case, my hunch is that we can take it as read that they would have sent the carb jetted properly for that kit. If memory serves, the default rough adjustment for the Pilot Air Screw is one and a half turns counterclockwise from fully screwed in. Try that and see if she idles better. Adjustments to the Idle Set Screw and fine adjustment by ear to the Pilot Air Screw (maybe an eighth of a turn one way or the other until she just "sounds right") should be done with the engine nicely warmed up. There is also a three-notched needle setting inside on the slide, but try the screws first.

[ace.cafe]

Is the engine a 612?

I personally think a 32 is small for a 612.

[Bilgemaster]

I've got a single Amal 32 (Concentric Mk. I 932) with a one-into-two manifold on my Norton 750 twin replacing the pair that had been on there earlier (runs smoother and easier maintenance), and she plonks along quite happily. Granted we're talking about a twin with alternating intake cycles of 374cc per each cylinder draw, and I never ever pressed her hard, but I've got to guess that if Hitchcocks is selling that Amal as part of their whole big bore shebang, it must be at least adequate, if not perhaps optimal. His 240 is a pretty big main jet...I think it may be the biggest available for Amal Concentrics. If memory serves, I believe my Norton's running a 220.

[Adrian II]

Amal will sell you jets all the way up to a massive 1900, I'm guessing this is for methanol use. 

http://amalcarb.co.uk/mk-i-concentric-series/1000-series/jets/main-jet.html?p=5

Is the engine a 612?

I personally think a 32 is small for a 612.

Hitchcocks' seem to have a soft spot for the Mk1 Concentric, and 32mm is as high as they go since the old 1000 series was discontinued.  They do still stock 34mm Mk2 Concentrics, which you would have thought the 612 kit would have deserved, but if they only ported the cylinder heads to 32mm, I can see why they stuck at 32mm carbs.

A.

[ERC]

My 612 has an Amal 932/300 with a 040 main.  ERC