This is the Tower Hobbies .25 cu in (4.1cc) Car Engine with Pull Starter.

FEATURES: Dual ball bearing-supported crankshaft
          ABC cylinder and liner construction-"A"luminum piston,"B"rass
            cylinder liner that is "C"hrome plated
          Slide Valve Carburetor
          Purple anodized heatsink cylinder head
          SG (pilot) type crankshaft
          Two year limited warranty

INCLUDES: Tower Hobbies .25 cu in (4.1cc) Car Engine with Pull Starter, Glow
            Plug, Exhaust Gasket and instruction sheet

REQUIRES  Fuel: 2-cycle glow fuel with 20% nitromethane, 16% lubricant-
            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.
          NOTE; Do not use a fuel with a nitro content higher than 20%

SPECS:    Displacement: 4.11cc (.25 cu.in)
          Bore:  17.94mm
          Stroke: 16.4mm
          Practical RPM: 3000 - 42000
          Output: 2.5bhp/34000rpm
          Weight: 13.2oz  (374g)
          Distance Between Mounting Holes Same Side:     .83" (21mm)
          Distance Between Mounting Holes Opposite Side: 1.4" (37mm)
          Length from Starter to Front Bearing: 3.4" (86.8mm)
          Height from bottom of Crankcase to top of Head: 3.9" (99mm)
          Height from bottom of Mounting Tabs to top of Head: 3.3" (85mm)
          Width of Mounting Tabs:     1.8" (44.8mm)
          Diameter of Exhaust Outlet: .73" (18.5mm) including gasket

        Carburetor Needle Settings-
          High Speed Needle: Pre-set for break-in at 4½ turns from closed,
            set 2½ - 3 turns from closed after break-in
          Low Speed Needle: Pre-set 3½ turns from closed break-in
          Throttle Stop Screw: Approximately 1mm from fully closed
          Mid range needle - Flush with the outside of the body

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 03/14/07
                                                                         ir/jxs