O.S 18645 91HZ-R 3D Speed Black 61G w/Powerboost Pipe

This is the O.S. Engines 91 HZ-R 3D Speed Helicopter Engine in Black with the 91 PowerBoost Tuned Pipe.

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

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

Features

• O.S 18645 91HZ-R 3D Speed Black 61G w/Powerboost Pipe

• Designed for all-out 3D competition

• DRS (Demand Regulator System) ensures a steady fuel supply for 3D flights

• 165° exhaust timing for optimal horsepower and stable hovering

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

• 61G Big Bore twin needle carburetor is designed to develope stable horsepower at 70-80% throttle which is widely used in 3D flight PowerBoost pipe is constructed of polished natural finish aluminum and was developed exclusively for flights with 90 size helicopters

Specifications

•   Engine-

• Displacement: 0.91cu in (14.9cc)

• Bore: 1.091" (27.7mm)

• Stroke: 0.976" (24.8mm)

• Power Output: 3.6hp / 15,500 RPM

• Practical RPM Range: 2,000 - 16,000

• Weight (w/o Muffler): 21.27oz (603g)

• Crankshaft Size: 5/16-24

•   Carburetor Adjustments-

• High Speed Needle Valve: Turn approximately 30° (3-4 clicks) during initial adjustments, then approximately 15° (1-2 clicks) when making final adjustments

• Medium Speed Needle Valve: Turn approximately 30° (3-4 clicks) at a time

• Idle Mixture Control Screw: Turn approximately 5° at a time, turn left to enrich idle mixture and right to lean mixture

• Height from crankcase bottom to top of cylinder head: 3.9" (100mm)

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

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

• Distance between mounting holes opposite side: 2" (52mm)

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

• Distance/bottom of mounting tab to muffler screw holes: 1.8" (42.8mm)

• Distance throttle lever to center of engine: 1.6" (42mm)

• Length from front bearing to center of engine: 2.2" (56.4mm)

• Length from front bearing to backplate: 3.3" (83.8mm)

• Length from backplate to end of crankshaft: 4.6" (118mm)

• Length from backplate to center of engine: 1.1" (27.4mm)

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

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

•   Pipe-

• Length: 12.3" (313mm)

• Diameter: 2.0" (50mm) at engine attachment point

• Exhaust Outlet Diameter: 0.20" (5mm)

• Weight: 7.9oz (225g)

Contents

• 91 HZ-R 3D Speed Helicopter Engine, with PowerBoost Pipe, Exhaust Tube and Mounting Hardware, #8 Glowplug, Check Valve, 0.2mm Head Gasket 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