OS 91HZ-R-3D-P 18645

91HZ-R 3D Speed Features:
Designed for all-out, aggressive 3D competition.
Offers incredibly stable mid-range torque for awesome 3D flight
Carburetor inlet enlarged to 11.2 mm
Exhaust port timing set at 165°Combustion chamber shaped to match the big bore carburetor and advanced exhaust cylinder timingDemand Regulator System (DRS) guarantees a steady fuel supply to the carb at any attitude, on a full or empty tank and during the most abrupt throttle changes
Lightweight, machined cooling head
Crankshaft counter weight has been modified to reduce vibration at high RPM
Black anodized crankcase offers better heat dissipation