O.S. .21XZ-M Inboard Marine Engine w/21D Carburetor

This is the O.S. .21XZ-M Inboard Marine Engine. Based on the .21XZ-R, the .21XZ-M Inboard Marine Engine takes that 2011 IFMAR 1/8 scale On-Road World Championship race-winning technology and applies it to .21-size boat competition! Many of the performance features found on the .21XZ-R are here; and by utilizing a water-cooled cylinder head and big-bore carb, the .21XZ-M will assert its domination on the water with the same resounding success!


  • The cylinder head is water-cooled and blue anodized
  • The 21D big-bore carb allows for the use of high-nitro fuel
  • The crankshaft is silicone-filled for more efficient intake; two tungsten weights provide optimum balance for low- and mid-speed torque
  • The cylinder liner has seven scavenger ports and three exhaust ports, for better, more efficient combustion
  • The piston is balanced and lightened, and the con rod had been made more durable
  • An RP7 turbo plug is included
0.21 cu in (3.5 cc)
Bore: 0.640" (16.27 mm)
Stroke: 0.661" (16.8 mm)
Practical RPM: 4,000-45,000
Output: 2.75 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

Includes: 21D carb, RP7 turbo plug, flywheel collet, 0.2 mm head gasket, dust caps

This product was added to our catalog on July 18, 2011.

This item is discontinued and no longer available for purchase. You may want to search our site for a similar item.
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