motor turns over once, then stops?
 

I have an unknown 50cc quad. I have taken the bike apart to find out why it won't start. What is happening is I hit the starter and it one crank one cycle then stop/stick. I have the crank cover off and if I use my hand to get past where it is sticking it will crank another revolution then sick again. If I just good the button down you can see it try to get past the one point, then the battery cables start smoking. I removed the starter and hit the start button and it runs just fine. I also but a new battery in it too. Please I am at my wits end on this one.

Could be a "weak" starter, that runs but has not got the power to get over compression but it sounds like a partialy seized motor. Take the plug out and turn the engine by hand, if you still get a place where the engine "sticks," you've seized it.

I was starting to think it was the starter, do you know of a cheap place to order them from?

Try the plug out test first, I think you have seized it. If you don't know the maker, a new starter will be a problem as there are several different ones for 50cc Chinese quads. You could try eBay but looking the same does not mean it will fit, an Eaton 50 starter looks just like a Suzuki 80 one but they are not interchangable.

Same problem
 

when you say seized it are you talking about the motor of the starter ?

Could be either, that is why you turn the crank by hand with the plug out, if it spins freely, it is a starter problem. I have learnt a bit since then though, and would be looking for a bad battery or bad connections on the thick wires, including earths, before assuming a faulty starter.

Starter or piston. Like Merryman said, with the plug out, if it spins freely, it is a starter problem.