Bonneville America Forums Forums Technical Forums General Tech Backfire help from the TRiumph Gurus PLEASE

TRIUMPH GURUS,

My Dad's 2002 BA (which I am trying to seel to Oates but will not sell until I figure this problem out) is backfiring out of the left cylinder only. The right is running fine. I rode the bike approximately 2 1/2 months ago and it has been sitting since then. I started it a few times while it was setting but the battery died after leaving the key on. I just replaced the battery and the bike starts instantly. Actually better than my 2003 SM. My first guess was the carbs needed cleaning. Oldroadie said to check the "squirrel condoms" on each carb....they are fine. While investigating this I started the bike. It idles fine then seems to "hiccup" on the left side. I had a light pointing at the bike and can see a spray of fuel coming from around the boot connecting the carb to the cylinder. The clamps will not tighten anymore. It is wet with fuel around the boot and only on the left side. Could this be the culprit????

I have ridden the bike and it cuts in and out on the left side. When at top speed it finally straightens out and runs fine until you release the throttle and try to engage it again.

Any advice, help, etc would be greatly appreciatted.

Steve

Would an auto parts store have something that could be tried? Or something off a different type motorcycle? I am NO WHERE near a Triumph dealer.

So you think it seems more like the boot than the carbs needing cleaning?

THANKS

Oh wait...I just re-read it....the clamp. Not the boot itself. Ok its time to sleep now since I cant read and comprehend....

I am no expert here but....
Dont the boots have different size opennings? Could one be backwards causing the leak?
I noticed this when I did my re-jet...one boot went on no prob and the other one wouldnt tighten...removed and flipped and no problem after that.

PM sent addressing manifold boot issue.

The carb rubbers definitely have a direction

Check out snekeptp's photo:



Look at the left clamp right in the middle and notice that 'tab' sticking up? btw, also notice the awesome job Pete did polishing his bowls, manifolds, and tops!!

Hey, Pete, you're missing the vacuum cap on the manifold side...

(Ok, so I do know that he knew that and corrected it after taking his great photo, super polishing job...makes me feel lazy)

The carbs have NEVER been off so i doubt they are on backwards.

What picture are you talking about? I looked in his member gallery and do not see it.

I see the picture now....

On the left side I have one nipple with black rubber over it and the front one on the cylinder has some kind of wiring or sensor or something coming from it. It is this way on both the 2002 BA and my 2003 SM

Quote:

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and the front one on the cylinder has some kind of wiring or sensor or something coming from it.

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that would be the vacume line up to the air injection ( ai ).
most have this removed as it is the cause of the pipe blueing
on stock bikes.

as for the fuel leak at the maifold , I would say that is you vacume leak right there.

get those clamps replaced , make sure the boots are seated
correctly and snug everything .
then see how she runs.

Sounds like an easy fix according to these guys.

Well I cannot find clamps narrow enough to fit in the grooves in the boot. I removed and repositioned the front clamp so that where it was leaking was on the clamp not the area where the two pieces come together. The boots are seated up against the tabs on the cylinder so that looks fine to me. I checked Advanace Auto, NAPA, A local hardware store and a marine supply store and could not find clamps that are narrow like the ones on the bike.

The bike still hiccups during idle from the left side. When the choke is pulled OUT and warming the bike up it hiccups worse and there seems to be a fuel drip from the plunger on the choke where it enters the left carb.......

Any advice now? This sure seems like a vacuum leak but I cant find it

Rewrite of all symptoms....PLEASE HELP

1. Bike starts fine
2. With choke pulled out the bike hiccups like there is a vacuum leak somewhere. When it does this fuel drips from the plunger of the choke where it enters the left carb.
3. Once warmed up the bike idles with some hiccup.
4. When trhottle is engaged to rev the bike the LEFT cylinder will backfire and a few times it has cause a flame backfire out of the left pipe.
5. When riding the bike it is hard to get moving in first gear because the left cylinder cuts in and out. Once moving the bike will surge because of the left cylinder cutting in and out. Once at a higher speed it will level out and run....until you disengage the throttle. When you roll on the throttle again it will cut in and out again.

Other info:
Stock Carbs-No jetting
AI still on the bike

Been to all the local moto shops. Everything they have is to wide to fit in the groove.

Where did you get the clamps? I will order ASAP if that is what I have to do but it would be much easier to get locally if I can figure out where to find them

you could test and see if thats the problem buy cutting some cardboard out of a pizza or cerial box and use it as a shim under the clamp. Thus making the clamp tighter and test it. If that fixes the problem cut some pieces of beer can or then go insearch of a clamp. Make sure the squirrel condoms are in place and have no signs of cracking.

Squirrel condoms all ok. AI is still on this bike and oldroadie said the other end may be a problem to. Gonna cut some carboard or beer can in the morning to fit and try to clamp down tight.....Ill let you all know

and last but not least........THANKS for all the help guys

Steve,

Slow down. The answer to your questions are underfoot.

Option one: Use the clamps from your 2003 SM on the 2002 BA.

Option two: Shim the clamps per Ian’s post above

Option three: Try to obtain some clamps from your local motorsickle shops

Gemstone Customs
137 5th Ave, Huntington - (304) 697-7433

Huntington Motorcycles Inc
4900 Waverly Rd, Huntington - (304) 429-2575

Dicks Cycle Shop
4352 Ohio River Rd, Huntington - (304) 696-9547

Order some clamps NOW. You’ll need them.
marine grade stainless steel clamps
SS Intake Manifold Clamps

Thanks for the input, guys. Hopefully he gets it figured out and its a simple fix.

I was at a Mazda, Porsche dealer making a del. and saw some hose clamps and got 4 of them. They are narrow with a slight curve up on the outside edges and works outstanding. Just a thought check with the import car dealers. They are stainless steel also. Phil

steveih,
Dood, check all of your plug wires, COIL wires (especially the two in the front of each) for snuggieness. Sounds like you are losing spark to one side intermittently.
That, or a vacuum leak.

I am getting ready to shim the clamps now....

What i meant is that the area the clamp come together (the two ends) was repositioned so that is was not over the suspect area. I was jut grasping at straws because i did not have a viable clamp option.

The motorcycle shops localy are Aholes...I stopped by two and they said we have nothing like that. I figure they do but I have had issues with them before and told them what I thought of their service so that probably doesnt help the matter. Also two of the ones on your list are closed now.

Im off to the garage...

Thanks for the effort, Steveh.

ALL,

Thanks for the help. When i removed the clamps to shim I found the culprit. Believe it or not the boot itself was dry rotted...Actually it looks like it was pinched and then caused the breakage. I couldnt see this with the clamp on because it was on the inner side of the carb. My dumba$$ should have looked closer a few days ago Good ole Dad must have worked on it at some time or it was put on crappy at the factory.

Here is a picture. I will be ordering two new boots and four new clamps. This should fix it for sure.



Thanks again for the help and I know Oates appreciattes it too.

Glad to hear and see you found the problem. Thx for sharing the solution with us.

That sure would cause the problem!

Easy fix though...

Easy fix and no doubt that is a problem. Be sure to put the new rubbers on correctly. they have sort of an angle to them so the carbs sit level,top wider than bottom.

Quote:

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Ok
lets get this finished

the divider between the clamps is wider on top
narrow on bottom.
now for the front to back ( engine to carb )
there is a small raised tab on the top of the boot
this is the front ( engine ) side of the boot.
see arrow in photo

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this should help

Thanks for the picture Pete. That will help when putting the new ones back on.

Again thanks to all who gave advice while figuring this out....this website and the people on here are a great resource

That tab isn't on all of them. When I put Toms back there was no tab.

I hope you ordered two sets of manifold rubbers? Refrigerate the spare set as you will need it in a year or so...The one you showed us that was on your Dad's sickle was majorly dry rotted. Go ahead and get some squirrel condoms too. Refrigerate them too. Or bring them inside a climate controlled environment. Your environment appears to shelter a derivative of the Andromeda Strain.

Yeah i have no idea why it did that. I think it was pinched during instal or my dad pulled the carbs at some point and installed it that way accidentally. There are no signs of deterioration on the right side. And none on my SM. Seems like a fluke to me. The bike has always been in either a storage building or a garage. No real climate control though.