The WW961BCVRS Triplex General Plunger Pump is designed for high-pressure washing. The plunger pump comes with a gasoline engine mounting flange for engines up to 13 HP. The pump features ceramic plungers, an unloader valve, reverse shaft, a forged brass manifold with a 4:1 hydrostatic rating and a die cast, anodized aluminum oil-bath crankcase. For lubrication, fill the crankcase to the top on the oil gauge window with non-detergent SAE 30W oil. The oil needs to be changed after a 40-hour break in period, then every 3 months or 500 hour intervals afterward.