Sounds like the motor is not getting enough fuel when you give it more throttle. I would assume it might be something in the fuel line (clogged fuel filter, dirt in tank, dirty carb). I would also take the carb off and completely clean it out with carb cleaner (have someone experienced help) and if cleaning these components doesn't help, then it is most likely in the jetting of the engine. You may need to have a richer jet setting installed on the carb to help with the high end bog. Goodluck buddy

The "why" question could not be more worthless if it tried. Look, you claim this KX-100, whatever it is, was in a repair shop. Mechanics warranty their work. Why is it not logical to return the KX-100 to the shop that did not fix it correctly? Asking for guesses as to the repairs of mechanical things online is neither wise nor smart. Mechanics fix machines. Go find one.

The carbouretor is having a hard time making the transition from idle or midrange to the main jet. Try making your idle and or midrange mixture richer. James is right--start with cleaning the carb. If you quit letting other people work on your bike you will always know exactly what it's doing.

Well first off. The bike does not have a warrenty so thats why i havent took it back. And second it was their fault it was put in there in the first place. So i wont be going back there. Im taking it to someone tomorrow i just thought maybe i could ask and get some answers before i took it!

I just got my KX 100 out of the shop. They replaced my throttle, cylinder and my piston engine and etc.. But i drove it today and it cuts out when i start to go full throttle. Any suggestions of why? Is starts fine and idles good. Help pleassee!