This scooter frame is one that you can buy from toy shops.
The motor is an echo, and is thought to be about 21cc
It is driven by a 1in spindle which was made on a lathe and has criss-cross grooves in it for traction on the tyre
Wheels are 16in nylons with "scooter tyres" on them.
Top speed is 42km/h with reasonable acceleration (for a small motor)