We talk about it a lot, but crankcase pressure is vital in making the golf cat run. When parts like the E-Z-GO Marathon Gas 2-Cycle Oil Seal blow out, it causes that pressure to be reduced or drop to nothing. The biggest thing this affects is the fuel supply to the motor. Your golf cart fuel pump relies on the in-out pressure created at the crankcase base to draw the fuel from the tank and shoot it up to the carburetor. The carb does create suction, but it is not enough to draw the gas directly on its own and must have the aide of the crankcase-powered fuel pump to accomplish the task of getting the gat to the engine.This golf cart oil seal is for the EZGO marathon models that are two-cycle. It will work on the fan side or the clutch side of the crankshaft, depending on the year of your golf cart. Call Buggies Unlimited and get one coming to you today. The only thing you will regret is not having done it sooner.