Description: This bike engine kit includes all of the necessary items to turn your pedal bicycle into a motorized speed demon with easy to follow instructions and phone support if needed. 50mm bore single piece cylinder/head (increased weight capacity, lower operating temps, easier starting, sustained power output across varied rpm range) Upgraded Tunable High Performance Carburetor. Features: Choke lever on the handlebars, Main jet. (Can be re-jetted), Pilot jet, Copper oil needle , Idle RPM Screw, Idle Air Screw delivers more fuel with the choke on, instead of restricting air. Great for cold weather starts! Upgrades include：44 Tooth Sprocket, Red Speed Carburetor, and Upgraded CDI. 4 bolts attach the engine to your bike frame and this kit comes are 8mm vs the standard 6mm. That means the mounts are twice as strong and twice as secure. Specifics: Bore＆stoke:50mmx40mm Ignition Mode:CDI Ignition Max.Power:3.2KW Compression ratio:6﹕1 Transmission ratio:18﹕1 Cooling:Air-cooling Starting:Kict starting Shifting way:sprocket Lubricating oil:Two-stroke machine oil Max.speed:48km/h Sparking plug:Z4C 16MMM Max.Load capacity:180kg Tank capacity:2L Fuel Type:90# Fuel consumption:5L/100km Engine type:Gasoline engine N.W ：11kg G.W：12kg Ctn size：47*43*17CM