I just recently got a duratrax nitro evader st. Its been running really good but it wheelies on asphalt a little to much for my liking. I tried and loosened the slipper clutch but it just seems like no matter what it wont slip. I can take off the spring and it still wont slip. I also cant get the the whole slipper clutch off without really scratching the whole thing up. Any ideas on what i should do????? thanks