This is the O.S. 21XZ-B ABC Engine with 21J2 Carburetor for 1/8 scale Off-Road Buggy Racing. ****** 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: Epoxy filled crankshaft ABC piston and liner construction "A"luminum piston fitted to a "B"rass cylinder liner that is "C"hrome plated 21J2 slide valve carburetor with 7mm carb reducer that restricts the airflow helping to increase the amount of torque produced INCLUDES: O.S. 21XZ-B ABC Off-Road Engine with 21J2 Carburetor, Exhaust Gasket, P3 Turbo Ultra Hot Glow Plug, 7mm Carb Reducer, Instruction Manual, 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: 4,000-40,000 Power Output: 2.55 PS, 2.51 HP/33,000 RPM Weight: 12.52oz (362g) 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: 3.4" (86.3mm) Width of Mounting Tabs: 1.8" (45mm) Distance from Backplate to Front Bearing: 2.5" (64.5mm) Distance from Center of Crankshaft to Front Bearing: 1.7" (44mm) Distance from Center of Crankshaft to Backplate: 0.81" (20.5mm) Carburetor Settings, NOTE carburetor is preset at factory and requires very small adjustments Needle Valve: Approximately 3.5 turns open from fully closed Throttle: Approximately 0.5mm open from factory setting with reducer removed Metering Needle: Rotate until slotted head is 1.5mm away from ball link body Mixture Control Valve: Rotate until slotted head is flush with carb body jxs 11/01/10 ir/jxs