Hi everybody. I lately got 1995 Vulcan 1500. . Since the bike has straight pipes and backfiring a lot when I got it, I installed stage 2 jet kit. The motor is still backfiring bad. Someone told me to check the air cut off valve on the carburetors. I pulled off the carburetors, and check the air cut off valves. One of 2 valves' diaphragm has been damaged. I replace both. Put the carburetors back on the bike. Still popping badly. Almost like fire cracker at Chinese festival. Even when RPM ascending it pops. Have any one been having the similar problem? If you have any idea what is the reason for this backfiring, please share your idea.

 

Could Exhaust be causing problem?.

Are there any baffles?

 

hmm, have you done a valve check yet, cam chain adjust? I need to look at a manual, but your ride may need some maintenance to go with your open headers.