21XZ-M Speed Inboard Marine
Get your racing boat up to Speed!
O.S.'s first marine engine under the Speed name is based on the 21XZ-R Speed on-road power plant, and is designed to deliver the same race-winning performance. Factory tuning optimizes the 21XZ-M's power potential, and it also shares the 21XZ-R's big-bore carb, black anodized crankcase and laser-etched, water-cooled head.
- The crankshaft is silicone-filled for more efficient intake; two tungsten weights provide optimum balance for low- and mid-speed torque
- An RP7 turbo plug is included
- The cylinder head is water cooled and black anodized
- Also Includes: Exhaust seal ring, head gasket set and dust cap set
Displacement: 0.213 cu in (3.49 cc) Bore: 0.641 in (16.27 mm) Stroke: 0.661 in (16.8 mm) Practical RPM: 4,000-45,000 Output: 2.76 hp @ 33,000 rpm Weight: 10.85 oz (307.5 g) Requires: 10-30% nitro boat fuel (20% recommended for break-in), exhaust system, glow plug igniter