This is the FS155-a P Four Cycle Engine with Pump System from O.S. Engines. FEATURES: Ideal for 120 size scale and sport models and aerobatic models requiring stable power and linear throttle response PD-08 pump and 70R carburetor integrated with regulator ensures stable fuel delivery regardless of model attitude and fuel level F-6020 three piece design muffler with center heatsink New internal lubricating system eliminates breather tubing from the crankcase Two year limited warranty through Hobby Services beginning at date of purchase INCLUDES: FS155-a P Four Cycle Engine with PD-08 Pump System, 70R Carburetor F-6020 Muffler, Header Pipe, type F Glow Plug, Needle Valve Extension Cable, Instruction Manual REQUIRES: Fuel: Glow fuel with 5-20% nitro content and no less than 18% lubricant content Propeller: 16x8-12 or 17x8-12 Glow Starter Field equipment SPECS: Displacement: 1.548 cu in (25.36cc) Bore: 1.323" (33.6mm) Stroke: 1.126" (28.6mm) Practical RPM: 2,000 - 10,000 RPM Power Output: 2.6 PS, 2.56 HP @ 10,000 RPM Engine Weight: 28.40 oz (805g) Muffler Weight: 3.35oz (95g) Carburetor Settings- Needle Valve: 2-1/2 - 3 turns from fully closed Mixture Control Valve: Factory set, make only small adjustments if needed, after adjusting needle valve as described in manual, turn 30° to lean idle mixture or 90° counterclockwise to richen mixture then back again 45° clockwise Width at Mounting Tabs: 2.6" 67mm) Crankcase Width below Mounting Tabs: 1.8" (47mm) Length from Drive Washer to rear of Carburetor: 5" (127.5mm) Height from Mounting Tab to Pushrod Cover: 4.5" (114mm) Height from bottom of Crankcase to Pushrod Cover: 5.4" (138.6mm) Distance between Mounting Hole Centers Same Side: 0.98" (25mm) Distance between Mounting Hole Centers Opposite Side: 2.3" (58mm) Distance/front Mounting Hole Center to Drive Washer: 2.5" (64.5mm) Distance/ Center of Engine to Drive Washer: 3.03" (77mm) Crankshaft Size: 5/16-24 jxs 02/15/11 ir/jxs