Is this when you first start it cold? Or after it has warmed up?
Does the throttle lever go all the way to the adjustable idle stop screw on drivers side?
If it doesn't,then the choke idle speed screw is too far in causing a too high speed.This screw is on the side of the carb on the passenger side down low at the end of the lower throttle plate.
Check this adjustment and see if it helps.
Mike.
