O.S. Engine 21XR-B Nitro Engine

O.S. Engine 21XR-B

The O.S. Engine 21XR-B nitro engine has been engineered to deliver maximum performance with minimal effort, while still being an affordable alternative for the up-and-coming off-roader. Proven O.S. technology ensures steady power. Ideal for any 1/8 scale buggy. Plus, the O.S. 21XR-B can be upgraded with many of the 21XZ-B’s parts for greater performance as a driver’s skills increase.

O.S. Engine 21XR-B Features

  • A blue-anodized aluminum head keeps the engine cool under harsh conditions
  • Simple, adjustable carb features easy tuning
  • Shares the same basic layout as the ultimate high-performance 21XZ-B engine, and can be upgraded with 21XZ-B parts

O.S. Engine 21XR-B Specs

Displacement: 0.213 cu in (3.49 cc)
Bore: 0.641 in (16.27 mm)
Stroke: 0.661 in (16.8 mm)
Practical RPM Range: 4,000-40,000
Output: 2.4 hp @ 33,000 rpm
Weight: 13.1 oz (370 g)

Part #: OSMG2055 – O.S. Engine 21XR-B Nitro Engine
MSRP: $229.99