Yamaha Primary Fuel Filter Cup Wrench YB-ACC04-1. Overview. The Yamaha Primary Fuel Filter Cup Wrench YB-ACC04-1 is a specialized tool designed to safely remove and install the clear plastic fuel filter cups used on Yamaha outboard engines. Engine fuel filter cups can be difficult to loosen by hand, and using improper tools such as pliers can easily crack or damage the plastic housing. This Yamaha-designed wrench provides the correct fit and grip needed to service the filter without causing dama