is it an hy motor? if it is chances are the carb is the culprit.....the walbro copy hsp use on the hy 30.5 is utter crap...there are two things you need to change before you start it; the carb and throttle servo, and trust me if you don't change the th servo it will runaway when you do finally get it running and find the nearest hard object to hit at wot