OS FS-91II Surpass 4-stroke engine has the new rear-mounted, updraft 60P carb, intake manifold, and coverplate. Helix gear-driven camshaft supported by ball bearings. Ringed piston. Does Not use choke valve, but instead an electric starter to start. Grease-packed twin-sealed corrosion-resistant rear ball bearing. Two Year Warranty. This product includes one assembled engine w/carburetor. One type #F glow plug. One muffler w/manifold. One set of instructions 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 synthetic/castor 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 because it has 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.
Propeller (see SPECS)
Starting and Field Equipment