had problems with engine missing when cracking the throttle and then, with just alittle throttle. Played with cable adjustment on handle bar and finally set it back just before clutch grabs. Haven't tried any hills yet, just around the pavement at home. runs strong in hi. But-- put it in reverse and give it throttle and it will kill the engine. What's up?? Looking for some more help??? Hard to believe that the cable ajustment is that touchy......What's really puzzling is it ran great one day and the next it ran like s--t.. and still does????