Suzuki GS650 Engine/Carburetor Tuning

Описание

I need help fine-tuning the engine on my 1981 Suzuki GS650 motorcycle. I am having an issue with my engine bogging down after 6000 RPM when I give it full throttle. In this video, I demonstrate the engine's abnormal behavior starting at 2:30. At 8:25 a view of the throttle and the tachometer is shown. I have gone through the carburetors thoroughly, I have checked the spark and compression in all the cylinders. Cylinder 1 and 4 have black soot covering the spark plugs, Cylinders 2 and 3 have a white cap indicating a lean condition. I'm sure this is a carb/air/fuel problem since the bike runs FINE with starting fluid. Could this possibly be a symptom of the bike's petcock not working properly causing fuel starvation? Thank you guys for your help it is much appreciated.