This is the O.S. 21XZ-R Version II ABC Engine with 21M Carburetor for 1/8 scale On-Road Vehicles. ****** Because of the expressed racing nature of this engine, ****** ****** it is NOT covered by the O.S. 2 Year Warranty ****** ****** per page 8 of manual. ****** FEATURES: Tungsten-weighted silicone filled crankshaft creates optimum balance for consistent low and mid speed torque ABC piston and liner construction "A"luminum piston fitted to a "B"rass cylinder liner that is "C"hrome plated Liner has seven scavenger ports and three exhaust ports for more efficient combustion 21M slide valve carburetor with 9mm carb reducer that restricts the airflow helping to increase the amount of torque produced INCLUDES: O.S. 21XZ-R Version II ABC On-Road Engine w/21M Carburetor, Exhaust Gasket RP7 Turbo Glow Plug, 9mm Carb Reducer, Flywheel Collet, Instruction Manual, 0.2mm Head Gasket and two Dust Caps REQUIRES: Fuel: 10-30% nitro content, 20% recommended for break-in Exhaust System: Depending on vehicle Glow starter, fuel tubing and track equipment SPECS: Displacement: 0.213 cu in (3.49 cc) Bore: 0.640" (16.27 mm) Stroke: 0.661" (16.8mm) Practical RPM: 4,000-45,000 Power Output: 2.75 PS, 2.71 HP @ 33,000 RPM Weight: 12.06oz (343g) Distance Between Mounting Holes Same Side: 0.83" (21mm) Distance Between Mounting Holes Opposite Side: 1.45" (37mm) Height Bottom of Mounting Tabs/Top of Cylinder Head: 3.45" (87.7mm) Width of Mounting Tabs: 1.8" (45mm) Distance from Backplate to Front Bearing: 2.6" (65.6mm) Distance from Center of Crankshaft to Front Bearing: 1.7" (44mm) Distance from Center of Crankshaft to Backplate: 0.85" (21.6mm) Carburetor Settings, Needle Valve: Approximately 3 turns open from fully closed Throttle: Approximately 0.5mm open from factory setting with reducer removed Metering Needle: Rotate until slotted head is 0.5mm away from ball link body Mixture Control Valve: Rotate until slotted head is flush with carb body jxs 07/25/11 ir/jxs