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

       ****** 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
          Demand Regulator System ensures consistent fuel delivery from full
            to empty
          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
          61F Big Bore carburetor is designed to develope stable horsepower at
            70-80% throttle which is widely used in 3D flight
          Crankshaft counter-weight reduces vibration at high RPM

INCLUDES: 91 HZ-R 3D Speed Helicopter Engine with #8 Glow Plug, Aluminum Check
            Valve, 0.008" (0.2mm) Head Gasket,, Control Arm 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
          Muffler-Depending on heli

SPECS:    Displacement: 0.91cu in (14.9cc)
          Bore: 1.091" (27.7mm)
          Stroke: 0.976" (24.8mm)
          Output: 3.6 PS, 3.55 HP/15,500 RPM
          Practical RPM Range: 2,000 - 16,000 RPM
          Weight (w/o Muffler): 21.27oz (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 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

                                                                   jxs 04/08/11
                                                                         ir/jxs