Small Engine

Honda GX390

4-Stroke

The Honda GX390 is a 389cc 4-stroke overhead-valve engine and the top model in Honda's single-cylinder GX commercial series, powering large pressure washers, high-output generators, log splitters, and construction equipment requiring sustained torque. It uses a Keihin float-type carburetor and accepts NGK BPR6ES or Champion RC12YC spark plugs. Oil quality and change intervals are critical at this displacement — Honda specifies SAE 10W-30 with changes every 100 hours. The Keihin carburetor float level and main jet are the primary fuel system service points. One of the most widely remanufactured small engines in North America.