Used MEP002A – MEP003A Fuel Control Unit Onan 147-0312. This does not include the O-ring (GA407743) that can be purchased here as part of a complete pump rebuild kit (Ambac M50 Fuel Injection Pump Gasket Rebuild Kit for 50-2/4A-80A-9540A, KT85166). It will come with a used O-ring, but this should be replaced prior to installation. It does include the fuel control (CU8513A, Onan 147-031). Note we believe the part number 147-031 is missing its last digit, but this is the number that appears in many manuals.