Bonneville T100 Afterfire When Deceleration

My Bonneville T100 is after firing or backfiring when downshift. Any suggestions as to the cause and fix?

 

Air leak at header pipes?

 

Guillermo Salina
What pipes are you running and have you disconnected anything like the induction kit on the head to airbox. And a lot of aftermarket exhausts do pop a bit on over run. I quite like it if it is mild. If not happy get it remapped and set up for any items disconnected. Would not worry to much as it is only unspent fuel in the exhaust system.
Regards
Joe.

 

If you’ve put after market pipes on try disabling sai, you can do a quick test by removing the rubber pipe from the air box and blocking the pipe with a marble or cork.

 

They are the stock pipes and I have made no changes. I noticed the left pipe has a little play and can be wiggled a bit.

 

I don't know much about motorcycle so I don't understand all the suggestions. Take a look at the Gap in connecting the exhaust pipe. I tried to reduce the space but I'm unable to do so based on where the rear foot peg is. I've tighten the clamp but there still some play in the pipe. I don't want to over tightened and crimp the pipe.

 

If you mean there is play between the silencer and downpipe in the uk you can buy a paste called gun gun which you smear into the join then tighten the clamp and run the engine to harden .
Also I meant a leak at the top of the downpipe where it connects to the head, can you hear any air sound there if you rev the throttle.
Is the bike new, I think not ? But if so return to dealer to sort.
These fixes are based on older bikes, not sure about yours but dont see why not.

 

Has it already been over tightened? It looks like the bolt head might have pulled through the exhaust clamp.

 

just remove the silencer and put a light smear of silicone sealant around the edge that connects to the header pipe.
I find silicone is much better than gun gum as it does not harden and crack

 

I have a totally standard 2019 T100 and it is prone to a little popping on overrun. (I quite like it!)

 

Sorry that was a picture without the bolt on.

 

Sorry that was a picture without the bolt on.

I guess I'll enjoy the popping myself given it's not a big problem. Thank you all.

 

Yes, the bolt was obviously missing but the clamp looks damaged!!

 

It looks like you should have an M8 washer under the head of the bolt too. Part #47.

https://www.worldoftriumph.com/part...triumphmc/modelid/610811/block/100079506-1-2/

 

You're right, I am missing that washer.

 

You're right, I am missing the washer.

 

Here are two better pictures.

 

Same thing happened to me , can anybody point me as to where I can get new bracket etc Ta