Reset the high and low speed needles to factory settings. I am not sue what they are, but you can go online and find the manual on pdf file to find out. Then it should fire up and you can start tunning. To tune just turn the hsn in until you see no more improvment in engine preformance or smoke stops pouring out of the exaust. If there is not smoke you are running the enige to lean and it will burn up. Also everytime you make a adjustment you need to make a couple of high speed runs to clear out the engine and to see the effects. when you make adjustments only turn 1/8 of a turn at a time. Then tune the lsn just pinch the fuel line rihgt before it reaches the carb. IF it takes the engine longer 3-5 seconds lean out the lsn and try again.