How should I convert a spare 81 atc 200 motor into a beast?

[bill222]

I bought my third, fourth, and fifth three wheelers this weekend for 400 bones. They are 81 and 82 185 and an 81 200. One of the 185 is minty fresh its unreal, the other I am keeping for myself and am planning on building an mx inspired 185. The 200 is dead with thirty pounds of compression. I haven't ripped it apart to take a look yet but it pulls over fine. So I am planning on hopping up and rebuilding the 200 and bolting it into the 185 I am going to keep. The motor will get a port and polish, I would like to mill the head down to run race gas, and drop in a 12 to 1 wiesco top end bored 2.00 over. Any thoughts or other suggestions would be great.

[TheRealFatShady]

Too much power is said to cause the auto clutch to have problems, or so I've read. Might be easier to use an XR200 or 200X engine if you want one with a manual clutch.