The new OS MAX-91HZ-PS Engine is especially designed for 3D Helicopter competition. Intended to provide steady and constant power at all times irrespective of violent attitude changes, the OS MAX-91HZ-PS Engine is equipped with a newly designed PD-08 pump.

Displacement: 14.95cc. (0.912cu.in.) Bore：27.7mm (1.091in.)　 Stroke：24.8mm(0.976in.)
Weight：635g (22.4oz.):  Output: 3.4ps/15,000r.p.m.
Practical r .p.m .2,000～16,000r.p.m.