Marc D
Pack Dog
Hey guys. I have just completed replacing the jets to 158 and 55 , shimmed the needle ,etc as per Dave's carb mod as well as removed snorkel and smog pump, sponge air filter and FMF pipe are also on bike. Mixture screw is two turns out and bike idles and rides great now but it fires a shot on start-up. This is without touching the throttle or choke with engine slightly warm after a ride. Tomorrow i will check if this is still the case with a cold start. I'm in Gauteng. What does this backfire indicate, mixture too rich perhaps ?