randhall
06-11-2007, 03:35 PM
After my first tune-up, (1976 90/6) the bike runs great, smooth, all seems well except that I have a backfire popping when I let off the throttle. Valves set, fluids changed. The timing is good (S mark in the window at idle, F mark in the window at 3000+ rpm). Carbs synched with a homemade water namometer (did I spell that correctly?). I am new to all this, have followed Clymer's guide along with a few tech tips I have found through BMWMOA and ABC. The bike is stock, 22,000 original miles, everything works, but I don't know where to check to get rid of the backfire.
Any help you can send is greatly appreciated.
Any help you can send is greatly appreciated.