OS MAX-21XR-B VER.3

O.S. Engines have announced the soon release of their new 21XR-B Ver.3 3.5cc nitro engine. The sports engine incorporates the DNA of the ultra-successful O.S.Speed line, transplanted into a more budget-friendly package for the average racer. A newly designed crankshaft will improve engine response thanks to a different shape and timing while a more lightweight piston further assists with a crisp engine response on throttle input. The OSSpeed-style conrod will offer exceptional durability while a redesigned combustion camber insert optimises power supply especially in the low to medium RPM range while offering stable engine performance at high speeds. Other features include a redesigned cooling head, the engine uses the double adjustment 21 J3-1 carburettor and it comes with 6mm off-road and 7mm GT specific venturi inserts.

Specifications:

• Displacement: 3.49cc
• Bore: 16.27mm
• Stroke: 16.8mm
• Practical RPM: 4,000-40,000
• Maximum output: 2.45ps/33,000RPM
• Weight 381g
• Standard equipment: T-P3 glow plug, orange 6mm venturi, yellow 7mm venturi, exhaust seal