I decided to make a scooter with an F50 motor, a Chinese analogue of D8. He took the wheels from a motorcycle Tula. The handlebar and part of the fork were taken from an old Chinese bicycle. Welded frame from the profile pipe 20 to 40 mm. The engine was fixed on the side of the rear wheel, so that it would not interfere with the legs standing on the scooter. Polyk made 10 mm of plywood. The brake made on the rear wheel, drum. The maximum speed is about 30 km. h. How he did and what I did can be seen here.