This is the Ofna Jammin' .12 Rear Exhaust Off-Road Engine with Pull Starter. Ideal for the Ofna CRT.5 Mini Truggy. ABC construction "A"luminum piston with "B"rass liner that is "C"hrome plated Three port liner, bushing connecting rod Composite bodied Slide Valve Carburetor with Red silicone boot Red anodized aluminum cooling head SG type balanced crankshaft Ofna Jammin' .12 Rear Exhaust Off-Road Engine with Pull Starter Fuel: Car blend with 20% nitro content Glow Starter Glow plug Bore: .54" (13.80mm) Stroke: .55" (14mm) Displacement: 2.1cc RPM: 29,000 Claimed Horsepower: 1 HP Weight: 7.7oz (220g) Width between mounting holes same side: .43" (11mm) Width between mounting holes opposite side: 1.33" (34mm) Distance from coverplate to end of crankshaft: 3.42" (87mm) Height/bottom of crankcase to top of cylinder head: 3.46" (88mm) Height/center of crankshaft to top of cyinder head: 2.95" (75mm) For non-pull start version order OFNG5126. jxs 5/23/07 &