Your Yamaha Fuel Pump is a vital little tool in ensuring that the engine gets the gas it needs. Let's take this one from the top. Your carb is mounted directly on the air intake. It uses this massive amount of flow to create a venturi effect that helps draw the fuel from the tank. In fact, at full speed, the carb can draw the gas all the way from the tank without the support of any other parts. That is how strong the suction is that the carb creates.The airflow is not excellent at the lower speeds, and the carb needs help getting the fuel up to it. This is where the golf cart fuel pump comes in. This little unit is a diaphragm-based unit that uses the in-out pressure of the crankcase to draw the fuel from the tank and shoot it up to the carb. This is really only needed at the lower speeds. So, if you only notice a problem when you are trying to take off, but then the car runs fine at top speed, clean your carb and call Buggies Unlimited to replace the fuel pump.