My girlfriend has a 1995 Suzuki,650 Savage,One cylinder,Street bike. The bike has backfired out the exaust since it was new.She took it back to the dealer several times,but they could'nt fix it,so she just rode it that way.The bike only backfires when you let off of the gas and it winds down about half way or more.the bike runs perfict,except for the backfiring.I thought that it must be getting air in thru the intake or exaust,so I replaced the exaust gasket(between the exaust pipe and the cylinder head),and I replaced the rubber boot and "O"ring(between the carb and cylinder head),,I also adjusted the float in the carb(down) and took the baffles out of the muffler,but nothing helped. It stills backfires.Does anyone have a solution to this problem?"HELP"

 

Wayne, did you pull the spark plug(make sure this isn't cracked and the wire is in good shape)....and see what color the insulator was?...it should be a light tan, to medium tan in color...if not your fuel mixture isn't right..especially if you removed the baffles. This causes a leaner mix, than what it came with. you might have to adjust the mixture screw to richen it up.Has the timing been checked also?a vacume leak in any of the carb hoses will cause it to run rough,but not necessaily back-fire. I'd also get a good manuel , and go thru the trouble-shooting guide in it.. Hope this helps you...