Mugen Ninja is a high performance 3.5cc Off-Road engine, using today's most advanced technology. The engine has been designed for maximum strength and highest specifications for serious and real racing. Fabricated from the finest materials available, it will insure less friction movement for higher speed and more economical fuel consumption.

The engine, OEM manufactured by O.S. Engines for Ninja, is loosely based on their V-Spec with some custom features: the crankcase is from the O.S. 28XZ engine and does not feature the distinctive O.S. 'black' coating, the sleeve port design is a bit different from the V-Spec, head design, the crankshaft has the same 'DLC' coating as the O.S. Speed V-spec but without counterweights. All in all a mix up of a few O.S. engines and Ninja branding.

Basically this engine is similar to a 5-port O.S. V-Spec engine!