Backfiring When Bumpy

[DukeRed]

Went over an invisible speed bump far too fast last week on the TRX.
Since then it has a tendancy to backfiring when going over big bumps but only when I have the throttle fairly open. I noticed it didn't seem to do it when I had a pillion but it might just be because I was more gentle. Oil/Filter change 800miles ago meant to be every 500 if that would make any difference. Only other things I've done to it are changing to shorter tie bars and dropping front suspension but can't imagine that makes a difference.

Saying everything since it might be important.

Cheers
____________________
Enjoy Life There's Plenty of Time to be Dead
https://www.janoner.com

[stinkwheel]

A common cause of backfiring is an interruption of the power supplying the spark (as if you flicked the kill switch).

So, could be that when you go over a bump, something is momentarily switching the power off. How about the sidestand bouncing away from the cutout switch as you go over a bump?

Failing that, I'd make sure the battery terminals are tight and check the wiring where it goes past the bodywork, under the tank and the past the headstock for chaffing.

Another cause of backfiring is an air leak in the exhaust system. Could you have dinged it when you went over the bump and loosened one of the joints?

My money is on the sidestand though.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[DukeRed]

Now that you say it I've always had to put it in neutral to start even when clutch in. Once it's started once though I can start it with clutch in , in gear.

Also got the bike stuck on the exhausts the other day going over a two foot curb so could be that.

Or could be the fact that I don't have a kill switch and the wires are tapped up.

Cheers again Stinkwheel permanent font of knowledge.
____________________
Enjoy Life There's Plenty of Time to be Dead
https://www.janoner.com

[sickpup]

[DukeRed]

This is where my knowledge of mechanics falls short. The TRX forum are constantly talking about emulsion tubes. What do they look like? Where would they be? What would indicate they pointed backwards?

I always imagined them to be thickish rubbery white tubes .
____________________
Enjoy Life There's Plenty of Time to be Dead
https://www.janoner.com

[DukeRed]

Hmm, it appears to have got worse. It's not the side stand or battery connection. I doubt it's the kill switch.

Now when I go over big speed bumps 10mph with no throttle, clutch in the bike dies and I have to start it up again.

This makes me think it isn't an issue with the exhaust/ carbs etc and is definately something electrical. Anywhere else I could check? Had new sparks in about 3 months ago.

Edit - took it back to standard ride height but still did it so isn't float bowls.
____________________
Enjoy Life There's Plenty of Time to be Dead
https://www.janoner.com

[bish777]

just run through everything and make sure nothings loose, check the connector block to your ignition box for a start, or to the coil(s).
____________________
GSXR1100J