This is the 21XR-B (P) 1/8 scale Buggy Engine from O.S. Engines. FEATURES: Shares the same basic layout as the O.S. 21XZ-B and can be upgraded with 21XZ-B parts Ideal for up and coming 1/8 scale buggy racers and backyard bashers Blue anodized aluminum cylinder head 22(B) slide valve carburetor Natural finish crankcase Two year limited warranty through Hobby Services beginning at date of purchase INCLUDES: 21XR-B ABC Buggy Engine with Slide Valve Carb, P3 Turbo Glow Plug, Exhaust Seal Ring, two Dust Caps, Instruction Manual 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: .213 cu in (3.49cc) Output: 2.45 PS, 2.61 HP/33,000RPM Practical RPM Range: 4,000 - 40,000 Bore: 0.641" (16.27mm) Stroke: 0.661" (16.8mm) Weight: 13.5oz (370g) Crankshaft Size: UNF1/4-28 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" (86.5mm) Width at Mounting Tabs: 1.8" (45mm) Width of Crankcase below Mounting Tabs: 1.2" (31.6mm) 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 02/28/13 ir/jxs