OS FS-40 surpass four-stroke model aircraft glow engine has a rear-mounted updraft carburetor. 30% larger intake valves than the original FS series. Helix gear-driven camshaft. Ringed piston. Ball bearing-supported camshaft and crankshaft. Two year warranty. This product includes one assembled engine w/carb and #F plug. One muffler w/manifold. One set of instructions, O.S. poster, and decal. (Wrenches, Choke Valve Extension, and Mounting Template Are No Longer Included per O.S.)

Fuel: 5%-15% nitromethane with 18% lubricant. Synthetic, castor, or a castor/synthetic blend may be used.
NOTE: Certain four-cycle fuels cannot be used due to low oil content.
However, SOME four-cycle fuels such as the Wildcat 4-Cycle 15% may be used due to its 18% oil content. When choosing fuels for this engine, the modeler must be sure to select a fuel with at least a 18% lubricant content.