460 rebuild question

[OneWithWood]

Did you do a leak down or vacuum test after installing the big bore kit?  A leaking seal will kill the saw in no time.
I put a big bore kit on my 460 a couple of years ago.  Running strong and dependable.

[ZeroJunk]

If the saw was tuned properly leaking seal or not it should not score the piston. Now, if it starts leaking or progresses and you don't hear it in time to adjust for it you will have problems. And, if it will no longer return to idle it should jump out at you. I have chased leaking seals by richening the mix until I got time or in the mood to replace them.