OS MAX 21XR-B Version II
Long Stroke
Powerful performance for weekend warriors
1/8 scale buggy competition is as fierce as it gets. You want every advantage possible — and it starts with the 21XR-B Version II engine.
This version of the 21XR-B power plant has been totally re-designed. It's even more reliable, and the new 21J3-I carb is easy to tune. The aluminum cooling head ensures steady power even under harsh conditions.
And when you're ready to move up to top competition, you can get up to speed with the 21XR-B Version II. This engine is upgradeable with high-performance O.S. Speed Parts, letting you realize your full winning potential. Equip your ride with the 21XR-B Version II, and start owning the podium.

• Engineered for up-and-coming 1/8 scale buggy club racers, with upgrade capability for competing at the highest levels.
  A dependable, low-maintenance engine that fits into most any modeler's budget.
  O.S. Speed parts are available for updating the outer and inner heads, crankcase, crankshaft and more.
  Includes Tuned pipe EFRA 2135 and manifold
  
  Displacement: 0.211 cu in (3.46 cc) 

Bore: .641 in (16.27 mm) 
Stroke: .661 in (16.8 mm) 
Practical RPM: 4,000-40,000 
Power Output @ 33,000 rpm: 2.45 ps/2.42 hp 
Weight: 13.40 oz (380 g)
Includes: P3 turbo plug
Includes tuned pipe EFRA 2135 and manifold