This is the O.S. Speed 21XZ-M Inboard Marine Engine. ****** Because of the competition nature of this engine,****** ******it is NOT covered by the O.S. 2 Year Warranty.****** FEATURES: DLC (Diamond-like Coating) on crankshaft, plus tungsten weights to minimize vibration, and silicone inserts to smooth fuel mixture 21D big-bore carburetor allows the use of high nitro fuel Laser engraved water cooled cylinder head INCLUDES: 21XZ-M Speed Inboard Marine Engine with RP7 Glow Plug, Exhaust Seal Ring, Dust Cap, Head Gasket Set and Instruction Manual REQUIRES: Fuel: Boat blend with 10-30% nitro content (20% recommended for break in) Exhaust system depending on application Glow starter and shore equipment SPECS: Displacement: 0.213 cu in (3.49 cc) Bore: 0.641" (16.27mm) Stroke: 0.661" (16.8mm) Practical RPM: 4,000-45,000 Output: 2.76 hp @ 33,000 RPM Weight: 10.85 oz (307.5 g) Crankshaft Size: 1/4-28 Carburetor Settings: Needle Valve; Turn clockwise until closed, open 1.5 turns, close 10-15° after running hull through 1 tank of fuel, repeat until approximately 2 liters of fuel have been consumed Mixture Control Valve; After getting needle valve adjusted, turn clockwise or counterclockwise in 10° increments to reduce excessive smoke (too rich) or to reduce speeding up momentarily (too lean) Distance between mounting hole centers same side: 0.83" (21mm) Distance between mounting hole centers opposite side: 1.4" (37mm) Distance/mounting tab to center of exhaust: 1.1" (28.5mm) Distance/mounting tab to center of cooling inlet: 2.2" (55.05mm) Distance from exhaust center to mounting flange bottom: Width not including mounting flanges: 1.2" (31.6mm) Width including mounting flanges: 1.8" (45mm) Height bottom of crankcase to top of intake: 3.1" (78mm) Length from Front Bearing/end of Crankshaft: 0.87" (22mm) Length from Front Bearing/center of Crankcase: 1.7" (44mm) Length from Center of Crankcase/end of Crankshaft: 2.6" (66mm) jxs 12/03/12 ir/jxs