O.S. Engines 21XZ-R VII Competition On-Road Engine w/21M Carburetor

This item is discontinued and no longer available for purchase. You may want to search our site for a similar item.
Low Price: $249.99
Discontinued Online

This is the O.S. Engines 21XZ-R VII Competition On-Road Engine. There's a revolution brewing in 1/8 scale racing. The 21XZ-R VII picks up where the original left off, ready to deliver dominating on-road performance with race winning fuel economy. The included 21M carb is unmatched for smooth, linear acceleration. The aggressive timing puts explosive acceleration and top-end speed at your fingertips, while surprising starting ease lets you unleash its race-winning potential right out of the box.


  • Silicone-filled crankshaft is balanced with tungsten weights for optimum balance and minimum vibration.
  • A 1-piece crankcase and 21M slide-valve carb for smoother transitions and higher top-end speeds
  • Redesigned 21M carburetor for improved fuel economy
  • Cylinder liner with 7 scavenger ports and three exhaust ports for maximum combustion and timing efficiency
0.212 cu in (3.49 cc)
Bore: 0.640 in (16.27mm)
Stroke: 0.661 (16.8mm)
Practical rpm: 4,000-45,000
Output: 2.71 hp @ 33,000
Weight: 12.1 oz (343 g)


  • RP7 Turbo glow plug
  • Exhaust seal ring
  • 0.01 & 0.02mm cylinder head gaskets
  • 8.5mm carb venturi
  • Flywheel collet
  • Exhaust, carb and fuel nipple dust caps 

This product was added to our catalog on March 22, 2012.