Can you use a head button that has slight pitting (caused by a blown bearing). I have lightly sanded the pitts. The sleeve/piston etc all ok. Will the compression be changed too much? The pitting is not in the chamber of the button, just on the flat edge.
I have ordered a new button but would like to try the sanded one while waiting.

It'll work fine.

if you sanded it down pertty good, take out one thin shim...should be good to go....

If you radiused the edge between the "bubble" and the squish band, it can affect the power output. The best remedy is to put the button in a lathe and set the cross slide at 5 degrees and take 2-3 thou off the squish band face.

I slightly sanded the squish band. It still has slight marking on it. The good news is it works ok with no power loss. I have a new button on the way just in case.

About the only way you will notice a power loss is on an engine dyno. Wow, we had an AC/DC concert in our city last night, I live 10 Km away from the stadium and I heard it[sm=eek.gif][sm=eek.gif][sm=eek.gif]