O.S. Engines would like to introduce new MAX-B21.

For 1/8 nitro Offroad and 1/8GT

MAX-B21 is easy to use from entry-level users to sports users and has excellent cost performance. Based on the O.S.SPEED series engine, it has a well-balanced combination of smooth speed and power delivery can be used in both on and off-road racing situations.
The outer head is based on MAX-21XR-B VER.3, it has been reduced weight for better performance. Also the shape of the combustion chamber of the inner head has been revised to improve combustion efficiency and response in the low speed range.
In addition, more stable idling, avoids stalling equals to easy carburetor adjustment.

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: 4,000-41,000
• Maximum output: 2.60ps/34,000RPM
• Weight 361g
• Standard equipment: T-P3 glow plug, orange 6mm venturi, yellow 7mm venturi, exhaust seal