So this is a x19? $130 is a good deal even if it isnt running. Well if your carb isnt put together correctly there could be a fuel flow problem, meaning either the cylinder is flooding with too much gas or your carb is sealed up and doesnt let the gas get to your cylinder. If the carb is put together incorrectly try putting it together right, before buying a carb rebuild set or a new carb, it is also possible that your floater is off. Or have u tried adjusting the idle screw yet? Try everything i listed above. If it still doesnt work, and u want to buy a carb rebukld kit or just a new carb go to www.pocketbikeparts.com or if u want to put it together correctly look up a diagram on google. The carb SHOULD be the problem, if the pocket bike is getting spark, nothings clogged or anything. The last option after cleani.g the carb is take a look at the wires tht are hooked up to ur key because if they are bad ur bike wont start unless the key is turned on and just kinda giving ur bike the signal to start hope this helps