If the piston/slide lifts too fast under excel it will create a flat spot. On an S.U... IF there is a flat spot it can be fixed it with a thicker oil in dashpot or a stronger spring. Your carb will have a spring in the top holding the piston down. Try lifting the piston there should be resistance. So see if you can find a stronger spring. If you cant find a stronger spring you could make the piston/slide heavier.
So. If the piston/slide rises to fast too much air will go into the engine creating a flat spot
Last edited by GARRICK.CLARK; 18-02-2019 at 05:09 PM..