Hi everyone, my first post so be gentle! I have just purchased a 250 and was wondering what I can do for upgrades and improvements. I bought it used but new in the box. It has the original coil on it. A friend of mine says he can wind me a new coil any size I want and really don't know what I can use. Can I use a D coil on this model? Like I said, I'm a newb so be kind.....Franco