O.S. Engines FX Series

The Remote Needle Valve - one of the most dramatic innovations of the FX Series - lets you make adjustments to the fuel and air mixture with your fingers safely away from the spinning propeller.

Engineered for superior, longer-lasting power.

61FX w/Muffler

91FX w/Muffler

The state-of-the-art in sport/competition engines! All FX engines come with remote needle valve - the feature most asked for! A longer crankshaft provides more secure attachment for spinner, prop and nut Dual ball bearing construction adds durability and longevity Semi-square head shape creates more fin area to increase cooling capacity Each engine comes with a high-performance carburetor and muffler with adjustable exhaust direction and built-in pressure tap 61FX & 91FX feature a remote needle valve that can be positioned two ways, to help you avoid cowl modification and preserve your plane's scale lines.