mrleo/inked1974
A couple of things you might already know.....the super rat uses 8 mm head studs,,,,,make sure your standard 66cc jug will accept the larger studs, the intake is larger, not sure about piston pin location/rod length differences. In any event, Gasbike has the super rat top end available. I think it is $70.
I have an almost new super rat top end available. Might have 5 miles on it. I put it on a standard 66cc bottom end and turned down the 8mm studs on the lower 1" of the stud and rethreaded them to thread into the 6mm holes in the standard base. I thought that would be better than retapping the holes in the base to 8mm since ther is not alot of meat in that area. Unfortuneatly the lower end rod bearings were noisey on the 66cc base so I pulled the motor. Inked-74...if you decide to abort the super rat idea and mrleo wants to sell the super rat base, I might be interested in buying the base. Would like to know a little bit more about the piston failure and how much junk might have gone into the base.