TOC-53 Displacement 53cc Bore/Stroke 44/35mm RPM Range 1,200 ~ 7,800 rpm Horse Power 5.5 HP Weight Engine - 3.1 lbs. Muffler - 5.6 oz. Ignition - 4.4 oz. Fuel Ratio 30 or 40:1 Break-In, 50:1 After Piston Rod 2 Needle Bearings Piston 2 Rings Crank 3 Ball Bearings (NSK) Carburator Walbro / 2 Petal Reed Valve Ignition CDI Auto Timing Advance, 4.8~6.0V CM-6 Spark Plug. Propellers 20x10, 22x8, 22x10, 23x8 2-Blade 3MM TOC 53 engine is specifically designed for R/C aircraft application. Abell Mfg