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.