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: 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

INCLUDES: 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

REQUIRES: 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

SPECS:      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)

                                                                   jxs 04/08/11
                                                                         ir/jxs