Bonneville America Forums Forums Technical Forums Exhaust Rejet or not rejet

I have fitted after market geniune TBA exhausts and experiencing backfiring on deceleration. Dealers say all part of it but do I need to alter the main jet. Backfiring I thought wasd due to unspent fuel which in turn could cause the lube to wash out and give piston slap. Any advice/help would be appreciated.

Welcome to the forum. Decel popping can be minimized by adjusting mixture screws. Plenty of info in tech vault.

You say they are TBA pipes. Is you bike a BA or SM? Are the pipes the Triumph Off Road (a.k.a. TORs)or stock?

If they are all stock, and it didn't pop before, look for leaks anywhere in the exhaust system. Most likely places are at the joint where the header and the slip on meet. Most folks here suggest using some high temp gasket maker on the joint. The other usual suspect is at the header/ head connection. The bolts seem to loosen up after a few thousand miles.

If you went to TORs or gutted stock pipes, you'll want to rejet.

what he said except expect a small amount of rumbling in decel if the engine is jetted properly. Not backfire but rumble.

yup Dogg's right. there should be a slight gurgle or rumble.

What you are hearing is may be lean pop from air being introduced back into the system (leak), or -is your Air Injection (AI) still on the bike?

Have you removed/disabled the AI? That's the tube you see next to the sparkplug. It adds air to the exhaust, that popping is unburned fuel burning in the pipe. Do a search on 'AI removal' and you'll find what you need.

BTW, welcome to the Sanitarium.

Welcome.

Here is what is pretty close to the bible of tuning these bikes

http://www.triumph-bonneville.com/images/Jet6.pdf

Worth it's weight in gold to gain a comprehensive overview of how to tune our bikes, with suggested setups as well.

Many thanks this should do the trick
Roger

Thanks Brian that guidance is what I neededalong with others. I now think I can overcome the problem.
Roger

Thanks to all you guys for your help research on your suggestions I am sure will solve the problem. Some great web sites suggested as well.

Thanks guys. The info was very helpful to me also!

Well now I am an enthusiast. Took your advice and sourced the blanking kit for the AI. What a sweet sounding BA I have now. Off to Poole Quay (Dorset) Tuesday night for the regular gathering of approximately 2000 bikes. Dream machine comp with bike of the week being awarded. Thanks for your help and others that contributed.