The O.S. SPEED B21 Adam Drake Edition 3 is an improved version of Edition 2, developed in collaboration with O.S. international team driver ADAM DRAKE, who is famous for his deep knowledge and sound technical advice.

Features

Includes T-2090 pipe
Developed in collaboration with O.S. international team driver and multiple ROAR Champion, Adam Drake
By adopting a boost bypass processing for the crankcase, the engine runs more smoothly
ADAM DRAKE's image colour, blue anodized aluminium is applied to the cutting part of the new outer head, and two-colour anodized aluminium with new design is used to reduce weight and lower the centre of gravity and improve driving performance
By adopting a cover plate with a built-in thrust plate, wear due to interference between the connecting rod and the cover plate during rotation is reduced and engine life is improved
Blue anodized restrictors, 6.5mm for buggy and 7.5mm for truggy comes standard
The inner head uses an O-ring to reduce vibration and improve dust resistance

Original source:
https://www.modelflight.com.au/os-engines-speed-b21-adam-drake-3-21-buggy-engine-with-t-2090-pipe.html