DO TWO-STROKE CARBURETORS HAVE ACCELERATOR PUMPS?
No. The intake velocity of a two-stroke is much lower than that of a four-stroke, and this gives a twostroke’s engine vacuum more time to do its work. The slower moving air effectively draws gas out of the jets and mixes it with air. With a four-stroke, there is a lag in engine speed as the throttle is opened. As a result, a four-stroke engine can’t draw enough gas up from the float bowl. That is where the accelerator pump comes in. Four-strokes do not have adequate vacuum when the throttle is cracked open. The fuel pump is a mechanically controlled circuit that squirts gas into an intake stream that is too weak to draw gas by itself.
