I have just bot a little 90 cc bike for 10$ it runs perfect when it is cold but when it gets hot it won't start, I am prity sour it is in the carb. When u take the carb apart there is a little needle thing, I think it is called the jet, there is 5 knoches on it, it was on the 2nd one from the bottom, were should it b?? On the outside of the carb there is a bronze screw in the middle, an the side were the air goes in there is a silver screw, about how many turns out should the b? I don't need exact measurements as long as they’re close, any other ideas on why it only runs when cold?? Thanx a lot!!

 

The littel needle thing is called the jet needle. It controls only part of the air/gas mixture.
The lower the clip is, the more gas that will be allowed into your motor at 1/2-3/4 throttle. If you raise the clip, then more air and less gas will enter the engine at this throttle position.
You should do a few plug checks and see where your jetting is at now.

 

Post some pics of the 90! I wanna see it

 

kk thanx i got the nedle down but whut do u do with thows screws, thanx[img]i/expressions/face-icon-small-smile.gif[/img]

 

SOUNDS LIKE IT MIGHT BE IN THE CHOKE?