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         This is the O.S. Max 21VG (P) ES Electric Start, Rear Exhaust
      Monster Truck and Buggy Engine with the 21F Slide Valve Carburetor.

          Excellent mid-range power for 1/8 scale buggies and trucks
                    to compete in ROAR sanctioned events.

FEATURES: Preinstalled E.S. Starter backplate is designed to use the Duratrax
            Kwik-Pit Super Start for the HPI Savage or the HPI Roto Starter
            System (HPIP8711)
          Advanced Bi-Metallic Liner (ABL) cylinder liner construction
            This process uses a double layer of plating material rather than
            one thick layer. This helps the metal bond to the cylinder and is
            more durable. Also, the plating process is more consistent,
            resulting in a more precise fit between piston and sleeve for
            better compression and longer life.
          Machined aluminum piston, 3-port cylinder liner and double bushed
            knife edge connecting rod
          21F two needle slide valve carburetor with insulated sleeve to
            prevent fuel vaporization
          SG (pilot) type one-piece crankshaft
          Two year limited warranty through manufacturer

INCLUDES: O.S. Max 21VG (P) ES Electric Start Monster and Buggy Truck Engine,
            21F carb, illustrated manual, exhaust manifold seal, #8 glow plug,
            and preinstalled E.S. Starter backplate

REQUIRES: Duratrax Kwik-Pit Super Start System or the HPI Savage Roto Starter
            System (HPIP8711)
          Car blend nitromethane fuel with 10-30% nitromethane content, 16%
            nitro content recommended as starting point
          Most of the fuels we carry meet or exceed the lubricant content
            required for optimum performance and maximum engine life. In the
            past, the conventional lubricant content used in fuel was 18%. But
            with new advanced technologies, fuels like Red Alert and O'Donnell
            for example, have a better quality of lubricants even though the
            percentages of lubricant content are lower. These high-tech
            lubricants provide exceptional cooling and protection.

SPECS:    Displacement:                  0.211 cu in (3.46cc)
          Bore:                          0.654" (16.6mm)
          Stroke:                        0.63" (16.0mm)
          Practical RPM:                 3,000-36,000
          Power Output:                  2.0 ps/30,000 RPM
          Weight:                        15.27oz (433g)
          Crankshaft Size:               1/4-28

          Factory Needle Valve Setting:  2.5 turns open from closed position
          Mixture Control Valve Setting: Adjust so that carb is approximately
                                         1mm open at idle
          Metering Needle Valve Setting: Flush with the ball link body

          Distance Between Mounting Holes Same Side:                21mm (.83")
          Distance Between Mounting Holes Opposite Side:            37mm (1.5")
          Height Bottom of Mounting Tabs to Top of Cylinder Head: 87.4mm (3.4")
          Width of Mounting Tabs:                                   45mm (1.8")
          Width of Crankcase Below Mounting Ears:                 30.8mm (1.2")
          Distance from Front Bearing to end of Crankshaft:       29.5mm (1.2")
          Distance from Center of Engine to Front Bearing:          44mm (1.7")
          Distance from Center of Engine to Backplate:            21.3mm (.84")

COMMENTS: Some notes on Slide Valve and Rotary Carburetors:
          Rotary Carbs offer a larger response in the middle of the power
            band. This works well for off-road applications when throttle
            response must be varied.
          Slide Valve Carbs provide greater response at the beginning and end
            of the power band. This works well for on-road and racing
            applications for fast take-offs and high speed.

                                                                    jxs 8/05/09
                                                                         ir/jxs



– If you need more information, use these O.S. resources –

E-mail: enginesupport@hobbico.com
Web Site: http://www.osengines.com/
Phone: 217-398-8970


 
Postal Address:
O.S.
3002 N. APOLLO DRIVE, SUITE #1
CHAMPAIGN, IL 61822  








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