trying to get the idle right on my '72 with amal 930's. the engine only responds to the right side carb. am i correct in thin king the synchronization is off? i can get him down to 800. the right side exh pipe is discolored a bit, plugs are a dark tan, occassional backfire or pop on the right side when revving from idle. tank is 2/3 full of av gas. bike runs super. i know i'm chasing my tail trying to get a steady idle w/ these old amals but am wondering why adjusting the left carb has no effect. thanx, rick