what to clean pistons with??

[Big Jay]

Soak the pistons in Simple Green. Carbon will come right off.

Jay

[rapidray]

Soak the pistons in Simple Green. Carbon will come right off.

Jay

This is the way I do it too! Ray.

[gpans]

Try 600 grit sandpaper!

I haven't got around to doing this to my bike yet, but I used 600 grit sandpaper on my carbonized moped piston and it ran so much better afterwards. Not only was there 1 mm of deposit, but the face of the piston was all scratched and chipped. The very fine sandpaper fixed that and smoothed down the face to almost glass. I have used that grade sandpaper before for buffing the contact surfaces of computer heat sinks to get better cooling performance. It can be expensive at auto stores, but its worth it.