Specifications: .Material: Metal .Model: 38cc-R Pro .Displacement: 38cc (2.33 cu in) .Performance: 4.2 HP .Speed Range: 1800-7300 RPM (Tested with 20x9 propeller) .Bore: 39 mm (1.54 in) .Stroke: 32.5 mm (1.28 in) .Static Thrust: 10.5 kg @ 100 m ALT (23.1 lb @ 328 ft ALT) .Static Thrust: 8.5 kg @ 1800 m ALT (18.7 lb @ 5900 ft ALT) .Compression Ratio: 9:1 .Fuel/Oil Ratio: 30:1 (Gasoline to Lubricating Oil) .Ignition Voltage: 6-14V .Glow Plug Type: E8 (or compatible OS G5) Heating Element .Recommended Propeller: 19x8; 19x10; 20x8; 20x10 .Weight of Main Engine: 1216g .Weight of Muffler Set: 73g .Weight of Aluminum Standoffs Set: 100g .Weight of Glow Plug: 3.6g .Weight of CDI(Ignition): 30g .Weight of Starter: 85g .Weight of ESC: 36g .Total Weight: 1542.5g (3.4lb) .Product Dimensions: 18.91 x 8.5 x 16.73cm .Package Dimensions: 20 x 20 x 20cm .Package Weight: 1750g .Packing: Box .Ages: 15+ Package Includes: .Engine *1 .Carburetor *1 .Exhaust Pipe *1 .Glow Plug *1 .CDI Igniter *1 .Engine Mount *1 .Propeller Shaft Adapter *1 .Gear-Driven Shaft *1 .Electric Starter *1 .ESC *1 .User Manual & Warranty Card *1