[corksil]

After talking to a few folks, I've learned quite a lot.

The 4mm overbore is out of the question. Having that much additional piston weight puts too much stress on the rods and the bottom end. Seems like that's the continual point of failure with a 4mm overbore. Rod failure at high RPM or the sleeve cracking due to lack of material between the two cylinders. I don't have the money to throw at replacing all that stuff, nor the time.

So then... 2mm overbore is the way to go. Pistons should be sent to whoever is doing the overbore, so they can be properly matched.

After a bit of time, I swapped over my ported head, exhaust, carbs w/filter, front forks including wheel, tire, brake rotor/MC etc, rear tire, sprockets, gearing... Basically all the good stuff went onto one bike. Now it's running perfectly, and I've got a line on some MR12 race gas. I'll need to order some bigger jets because I've got a dynojet 110 in there and I don't think I have any bigger sizes.

Also need to figure out how to fix the mangled pipe. The section I need is no longer available from the seller so I'll probably have to drill some holes and use a torch and some punches to get the thing straightened out.

The struggle continues!