I was jumping a 2 1/2 foot ramp and the last time I jumped it it flipped a couple of times and landed on the wheels and when I pressed the throttle, the engine excelerated but the truck didn't go anywhere then I pressed it again and it went. I ran it for about another 10 min. and it didn't do it again. But what do ya'll think that was slipping. Is that normal or is something about to go out? Thanx

check your clutch spur gear and all that jazz.....its good to do inspection after each run to make sure its all in order.