Owner's Manual

About the Yamato 80

The Yamato model 80 is a stock-racing engine. Like it's predecessors, this motor was developed specifically for use: in multi-billion dollar pari-mutuel boat racing industry in Japan. These motors are required to run heat after heat, day after day with perfect reliability at racing speeds. Therefore, they have been "over-designed" in relation to the job they perform.

In the United States, the American Power Boat Association (APBA) Stock Category (20SSH and 25SSR Classes) use the Yamato 80. The American Outboard Federation (AOF) and National Boat Racing Association (NBRA) and other local associations use the 80 motors in similar classes as well.

The Yamato model 80 is a water-cooled, two cylinders, 327.8 cc (20 cu in), and 30-hp/ 7,000-rpm gasoline motor. Features include a loop scavenging combustion system, pyramid reed valves, one piece connecting rod, precision ground full circle press together crank, ball and roller bearings throughout, high capacity magneto, integrated fuel tank, and an internally tuned megaphone muffler. The cooling system is supplied by the propeller forcing water into two intake orifices located aft of the propeller. The prop shaft rotation is counter clockwise. All exposed parts are made of corrosion resistance material. All fasteners are made of stainless steel with the exception of parts, which require additional strength.

The motors were manufactured from 1974 till 1979 at a rate of 1,500 motors per year. Approximately 1,100 motors were imported into the United States.

RPM Marine no longer offers the complete motor for sale!