The engine was a straight twin, two-stroke, air-cooled, oil-injected, dual rotary disc valve.

The engine's ignition air supply began in an air filter canister below the seat and was pulled through a large plenum chamber just above the transmission and behind the cylinder head then downward into the two internal passages leading to the carburetor housing feeding the carburetors.

The A1 Samurai motor was lubricated by the Superlube system, with 2-stroke oil directly injected in the intake tract.

[1] This combination of displacement (247cc), CDI system, and rotary discs produced 31 hp (23.1 KW) @ 8000 RPM gave the Samurai a power-to-weight ratio of 1 horsepower per 11 pounds of weight, a 0-60 mph of 6.6 second,[citation needed] making the Samurai as fast or faster than production competitors in its class.

[2] Kawasaki Mach III's successfully raced with Ginger Molloy aboard his "Green Meanie" finishing 2nd just behind Giacomo Agostini's MV Agusta in the 1970 500cc World Championship.