O.S 18641 .91HZ-R 3C Speed Red 61F

O.S 18641 .91HZ-R 3C Speed Red 61F

This is the O.S. Engines 91 HZ-R 3C Speed Helicopter Engine in Red.

****** Because of the competition nature of this engine,******

******it is NOT covered by the O.S. 2 Year Warranty.******

Features

• O.S 18641 .91HZ-R 3C Speed Red 61F

• Designed for all-out F3C competition

• Demand Regulator System ensures consistent fuel delivery from full to empty

• 170� exhaust timing for optimal horsepower and stable hovering

• Newly designed combustion chamber shaped to match the big bore carburetor and advanced exhaust cylinder timing

• 0.44" (11.2mm) Big Bore 61F carburetor for greatest power needed for F3C maneuvers

• Crankshaft counter-weight reduces vibration at high RPM

Specifications

• Displacement: 0.91cu in (14.9cc)

• Bore: 1.09" (27.7mm)

• Stroke: 0.98" (24.8mm)

• Output: 3.6 hp @ 15500 RPM

• Practical RPM Range: 2,000-16,500

• Weight (w/o Muffler): 21.2oz (603g)

• Crankshaft Size: 5/16-24

• Height from crankcase bottom to top of cylinder head: 4" (103mm)

• Height/bottom of mounting tab to top of cylinder head: 3.1" (79mm)

• Distance between mounting hole centers same side: 0.98" (25mm)

• Distance/mounting hole centers opposite side: 2" (52mm)

• Distance/center of muffler screw holes: 1.6" (42mm)

• Distance/bottom of mounting tab to muffler screw holes: 1.7" (42.8mm)

• Distance/crankshaft center to throttle control arm: 1.6" (42mm)

• Length from front bearing to backplate: 3.3" (84mm)

• Length from backplate to end of crankshaft: 4.5" (116mm)

• Width of crankcase below mounting tabs: 1.7" (43mm)

• Width between mounting tabs: 2.4" (61mm)

•   Carburetor Settings-

• High Speed Needle: Two turns open from fully closed

• Medium Speed Needle: One turn open from fully closed

• Idle Mixture Control: At basic position when engine leaves factory

Contents

• 91 HZ-R 3C Speed Helicopter Engine with #8 Glow Plug, Aluminum Check Valve, 0.008" (0.2mm) Head Gasket,, Aluminum Control Arm, two Needle Adjusting screws and Instruction Manual

Requirements

• Fuel: 10%-30% nitromethane with at least 18% lubricant. Lubricants may be either castor or synthetic oil or castor/synthetic blend.

• Field Equipment: glow starter, fuel bulb, fuel can filter, fuel pump hexagonal starting shaft (depending on brand of helicopter) electric starter, battery and fuel tubing

• Muffler-Depending on heli