This is the O.S. 21XZ-M 3.5cc Inboard Marine Engine.

        ****** Because of the competition nature of this engine,******
          ******it is NOT covered by the O.S. 2 Year Warranty.******

FEATURES: Designed expressly for 21 class boat racing
          21D big bore carburetor allows use of high nitro fuel
          Blue anodized water cooled head

INCLUDES: O.S. 21XZ-M 3.5cc Marine Engine with 0.2mm Head Gasket, Silicone
            Exhaust Seal, RP7 Turbo Glow Plug, two Dust Caps and Instructions

REQUIRES: Glow Fuel: Boat blend with 10-30% nitromethane content, use 20% for
            break-in
          Exhaust system depending on boat
          Glow plug igniter

SPECS:    Displacement: .21 cu in (3.5cc)
          Bore: 0.640" (16.27mm)
          Stroke: 0.661" (16.8mm)
          Practical RPM: 4,000 - 45,000
          Power Output: 2.75 PS, 2.71 HP @ 33,000RPM
          Crankshaft Size: 1/4-28
          Carburetor Settings:
            Needle Valve; 1.5 turns from fully closed
            Mixture Control Valve: Turn clockwise 10° to lean mixture or
             counterclockwise to richen mixture, adjust in steps of no more
             than 45-90°
          Distance between mounting hole centers same side: 0.83" (21mm)
          Distance between mounting hole centers opposite side: 1.4" (37mm)
          Distance/mounting tab to center of exhaust: 1.1" (28.5mm)
          Distance/mounting tab to center of cooling inlet: 2.2" (55.6mm)
          Distance from exhaust center to mounting flange bottom: 1.1" (28.5mm)
          Width not including mounting flanges: 1.2" (31.6mm)
          Width including mounting flanges: 1.8" (45mm)
          Height bottom of crankcase to top of intake:
          Height bottom of mounting flanges to top of intake: 2.6" (66.1mm)
          Length from backplate to end of crankshaft: 3.4" (86.5mm)
          Length from backplate to front bearing: 2.5" (64.5mm)
          Length from crankcase center to front bearing: 1.7" (44mm)

                                                                   jxs 05/24/11
                                                                         ir/jxs