I have an opportunity to buy a banshee with a 420 cheetah cub motor. The kid just wants to get rid of it because he can't get it to run right. The bike runs fine and starts easy, but it just won't hit the powerband for some reason. It used to but then he took the top end apart to replace all the gaskets and now it won't hit the powerband anymore. I thnk this could be an easy fix and a real good deal for me any help would be great. Thanks, Chad