2 cyl onan motor surges when you rev it up?

2 cycl engines are funny that way. There are two things you can check. 1 the air gap between your (coil) magneto and your fly wheel it should be set at 10 thousands of an inch, use feeler guage and make shure they are free of rust. This will give you the proper voltage for a good spark. 2 if you have two adj screws on your carb 1 is low speed (idle) the second is high speed. The low speed screw be turned right till it wants to stall then left till it wants to stall and then set in the middle. then slowly throttle up and do the same with the high speed. You might have to do this a couple of times to calibrate the carb. It sounds like an air fuel mixture problem and this should solve it. If not your carb needs cleaning. Good luck

JOHN at Rona
September 2004