First make sure you have the proper gas and oil mixture before trying to start scooter. This is the most common mistake people make. Mixture should be 32:1. Then you have to pump the primer bulb on the underneath side of the carburetor. Pump until you can see that gas has reached the carburetor. Try and start your scooter. Don't pull the cord more than 4-5 times. If the scooter doesn't sound like it's about to start then turn the throttle a bit while pulling the cord. Try this 4-5 times. If you still are not started then your carburetor may need adjusting.
Adjusting the carburettor.
From the left side of the scooter you will see a flat head screw toward the bottom of the carburetor. Turn this screw all the way in or clockwise then turn it out counterclockwise 2 1/2 turns. This is the factory setting for the air mixture.
Why does my chain keep falling off?
This can be caused by a bent sprocket or the chain isn't aligned properly. The chain can be adjusted in 2 ways. First you want to make sure the rear tire is straight. Just eyeball it and you should be able to tell if its straight or not. If its not, loosen the nuts that hold the wheel in place. Adjust the tension screws until wheel is straight. If your chain still looks crooked then you need to adjust the motor. To adjust the motor simply lay the scooter on its side so you can get to the bottom of the motor. You will see 3 screws. Loosen all 3 screws just a little. Straighten the motor until the chain looks straight and your chain should never fall off again.
How do I adjust my brakes?
You will see an adjustable screw next to your brake lever. Turn it counterclockwise until brake is how you want it. If brake still doesn't work good enough then you need to adjust the wire where it connects to the caliper or drum. Loosen the nut that holds the wire. Pull the wire tighter and tighten back the nut.