Phantom 85 Motorized Bike Hits 52MPH u0026 Could ve Gone Much FasterRated Power Rotary Speed 2.5Kw/5000Rpm (3 horsepower). By just simply pressing the kill switch, you can power off the engine and stop the bike. 80cc 2-stroke gas engine motor kit for motorized motorised bicycle push bike this kit allows you to can either pedal for riding your bike as normal, or release the clutch lever to start the motor with no pull starting of engine required.