I have an older model Gxsr 750 ( 90' ), and I recently put another jet kit ( carb ) on it about a month and half ago. Now its starting to back fire while rollin on freeway and just about threw all gears of acceleration. I changed the plugs, caps, and even coils. But its still back firing. At this point I feel the shop that put the Carb kit on should warranty ( excuse spelling ) their work, am I right..??
But I also have a gut feeling they may be scamming me for money.
The only other options I know of that may be making it backfire, is either electrical, or carb clogged. Does ANYONE have anymore suggestions they can possibly give me, or can refer me to a decent Mechanic in Southern Cali ( between Irvine and North San Diego )....??

 

did it run ok before the jet kit? how many miles on the bike?

 

Probably not it, but.... I used to have a backfiring prob with my katana. I rebuilt the carbs, tried everything. It turned out that my run/off switch had a loose connection inside and Just turning on and off would fix the problem.

 

yeah..its was running good, and it had a carb kit already installed.

 

Mike M. - I'll check the on / off switch, thanks. But I don't think that would make it backfire. Well no matter what, it'll be in the shop monday morning. Have a safe weekend fellaz..

 

something wrong with the carbs! i would say they got them set to rich and try some different jets!

 

Thanks JW..I'll look into it.

 

I doubt it's the carbs it sounds like an ignition problem. I don't know of any carburation problem that would result in a backfire except on deceleration which is most likely a vacuum issue. I'd check all your connections for loose wires as well as your ignition sending unit. If you have a shop that you can trust have them run a diagnostic on the safety switches also. Chech the kickstand safety switch as well they *** up all the time.