Ofna keeps taking it to the limit. The new Force .32 nitro engine will deliver all the horsepower you need to succeed, while maintaining the durability and affordability you've come to expect from the Ofna Force line of engines. This product includes Ofna Jammin' .21JPX Engine with turbo glow plug, instruction sheet and Jammin' sticker

Ofna recommends using 20% O'Donnell fuel
Muffler or tuned pipe depending on application
Some notes on Slide Valve and Rotary Carburetors:
Rotary Carbs offer a larger response in the middle of the power band. This works well for off-road applications when throttle response must be varied. Slide Valve Carbs provide greater response at the beginning and end of the power band. This works well for on-road and racing applications for fast take-offs and high speed.