O.S. Engines FX Series

Engineered for superior, longer-lasting power.

25FX w/Muffler
O.S. Engines 25FX w/Muffler

61FX w/Muffler

   The FX family begins with the economical 25FX and extends all the way to the 160FX, which produces almost three times more power per pound than more costly (and complicated) 41cc gasoline and multi-cylinder 4-stroke engines — and does it easily from a 2 lb. package.
   All FX engines feature dual ball bearings for durability and smooth operation, plus a low crankcase profile that allows for a proportionately taller, semi-squared head — a design refinement that increases cooling fin area and improves heat dispersion. Plus, you'll never have to worry about losing a prop during flight — the threaded portion of FX crankshafts is extra-long, to promote better engagement of the prop, nut and spinner and greater flight safety.
   The needle valve of every FX engine is remotely mounted for protection. An O-ring and ratchet spring minimize “creep” due to air leaks and vibration. Needle valves on the 61FX and 91FX can be positioned horizontally or vertically, to help eliminate the need for cowl modifications. The high-speed needle valve on the 60FX can be mounted horizontally, vertically, or separate from the engine, allowing even more installation options.
   FX engines have the same mounting dimensions as their SF Series counterparts, so replacement is “drop-in” easy. All (except 160FX w/o Muffler) include a muffler and all (except 25FX and 40FX) also include a glow plug. 2-year warranty.

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.