OS Engines MAX-R21 .21 Size Engine, 1/8 On Road Club Spec 1B900

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SKU: 1B900

O.S.Engine Nitro Motor

Club racers rejoice! The R21 is based on the Championship heritage of the R2102 engine and delivers an unbeatable blend of power and value for 1/8 on-road racing. Its crankshaft and piston/liner are designed with premium performance and easy maintenance in mind, which makes it an ideal choice for beginners. This engine is upgradeable with high-performance O.S. Speed parts, letting you realize your full winning potential. High performance. Low price. That's what you can expect from the R21, only from O.S.


  • The perfect power plant for rookies and club racers.
  • Newly developed crankshaft and piston/liner with the capability to upgrade later to a Spec-class performer.
  • RP7 Turbo glow plug.
  • 8.5 mm carb reducer.
  • Speed flywheel collet.
  • Exhaust seal ring.
  • Dust cap set.



  • Weight: 340g
  • Displacement: 3.49cc
  • Bore: 16.08mm
  • Stroke: 17.20mm
  • Power Output: 2.71 hp  @ 32,000 RPM
  • Practical RPM Range: 4000~44000
  • Includes: RP7 Turbo glow plug, exhaust seal ring, 8.5 mm carb reducer, dust cap set
  • Requires: Glow fuel, glow igniter, fuel filter, fuel bottle, starter and T-2080SC Tuned Pipe Set