Re: got my first chinese 50cc kit - need advice
Take your spark plug off and look at the color of it, what is it brown black white? If the color of it is white you are running to lean that is you motor starving for fuel,if it is brown your perfect, if it is black you are running to rich that means too much fuel. you can adjust how much fuel you motor is getting by where you have the c-clip on the needle that is inside your carb on the slide you move it up to get more fuel and move it down to get less fuel only move it one notch then test your bike at WOT for a minute or two then kill your motor let it cool then check your plug again.
How much do you have the idle screw turned in?
If you close the choke all the way does the motor die if it does not your intake has a major air leak either where you mount the flange to the motor, where you put the carb on or both. If you do have an air leak you can use some black or orange rtv gasket maker stuff to fix it. When you put it on the part that the carb goes on try not to have any of it on the end but around the pipe also let the stuff dry completely or most of the way for a perfect seal.