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

This item is discontinued and no longer available for purchase. You may want to search our site for a similar item.
Low Price: $394.99
Discontinued Online
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.