150cc gy6 engine problems

[hotrod1977]

I am working on a talon made by carter that has this 150cc gy6 engine.first i discovered that the start clutch was bad and also sheared the woodruff key so replaced and tryed to start but acts like timing is off. Any suggestions?
Thanks tracy

[EJ Mac]

Pull the spark plug out and get a straw to stick down in the cylinder and roll the motor to Top dead center, then pull the valve cover off and on the cam gear there will be 2 small holes that should be parallel to the valve cover mating surface and a big hole that should be pointing at the seat.