Specifications: Displacement: 1.22 cu in (20cc) Bore and Stroke: 1.26 x .98 (32 x 25mm) Compression Ratio: 10.5:1 REQUIRES: Gasoline with at least 87 octane rating; battery for ignition; Propeller Fuel Mixture: Break in with Lawn Boy(or similar non synthetic oil) at 32:1 Ratio per gallon / Use RedLine oil at 50:1 for long term use after break in. Fuel Octane Level: 93 Propeller Range: 14x10, 15x8, 16x6, 17x6 Ignition Battery: 4.8 - 8.4V Replacement Spark Plug: NGK CM6 Output Power: 2.5 HP at 9,000RPM Best Performance RPM Range: Idle Speed: 1,700RPM Weight, breakdown: Engine: 1.7lbs (660g); Exhaust: 2.8oz (80g); Ignition: 4.6oz (130g) Static Thrust: 13.14lbs (6.3kg) 328ft (100m) altitude / 12.6lbs (5.6kg) 5,900ft (1800m) altitude