O.S 18650 .91HZ Ring 61E

This is the O.S. .91HZ F3C Competition Helicopter Engine.

Features

• O.S 18650 .91HZ Ring 61E

• Designed specifically for F3C aerobatic competition

• Rectangular heat sink allows engine to be enclosed entirely inside cooling shroud

• 61-E carburetor with thermal insulator to block heat and a needle valve control lever to control mixture from transmitter, carburetor has three adjustment controls that enable independent adjustment at idling, hovering and high speed

• Five holes in the top of the piston route gases to the piston ring from within to form a tighter seal with minimum blow by

• Ball bearing supported crankshaft

• Heat sink type backplate

• Two year limited warranty through Hobby Services beginning at date of purchase

Specifications

• Displacement: 0.91 cu in (14.95 cc)

• Bore: 1.09" (27.7mm)

• Stroke: 0.98" (24.8mm)

• Output: 3.4 hp @ 15,000 RPM

• Practical RPM Range: 2000-16,000

• Weight Without Muffler: 1.36lb (618g)

• Crankshaft Size: 5/16-24

• Height from crankcase bottom to top of cylinder head: 3.9" (99mm)

• Height/bottom of mounting tab to top of cylinder head: 3.2" (81.2mm)

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

• Distance between mounting holes opposite side: 2.04" (52mm)

• Distance between muffler screw holes: 1.6" (42mm)

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

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

• Length from backplate to end of crankshaft: 4.9" (125.6mm)

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

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

• Carburetor Needle Settings:

•   High Speed: 2 turns out from fully closed

•   Mid Range: 2 turns open

•   Mixture Control (low speed): indentation on screw head straight up and down (vertical)

Contents

• O.S. .91 HZ F3C Competition Helicopter Engine with #8 glow plug, needle control lever, extra 0.2mm head gasket, cap 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