I have rear cylinder miss fire under load. have replaced plugs ignitor unit, swapped coils,replaced rear carb,still rear misfire under load I have run the valves, compression check.Ive checked resistance of signal generator.It was within range.Please,any Ideas on it, its a 91 suzuki vx800 with 7,000 miles.I am a 58 year old auto mechanic with more than 40 years experience.This one is whuppin my rear end.I would really appreciate any input THANKS aug 6 2012