Blacksheep

Hey all, I'm new here so I thought I'd start at the deep/stupid end.

I'm currently rebuilding my little 600, and one of the myriad of things I want to fix is the front piston slap/ringing that is so common on this bike.

From what I understand the only real way to fix it is to swap the piston. Does anyone know of anything that would stop me swapping a piston from a rear cylinder and using it in my front one? Because they are a hell of a lot easier a cheaper to get hold of. Basically are the two pistons different in any way I haven't noticed?

Or even simply skimming a tiny (and I mean tiny) bit off the piston skirt of the current piston? Haha. That would be fun.

Thanks in advance!