3120xp "safe" squish

[Iron.and.bark]

You will have no trouble at all with a squish of .022". I've seen an 066 come from the factory with a squish of .017". It's been a while, but my 084 worksaw has a squish of .020"-.025" and turns 14,000 RPMs at WOT. It's been used for stumping and pulling a 72" bar nearly buried in oak.

Sorry to pull up a slightly old thread.
Would a squish of around .025" be safe on a 3120 pulling a 72" bar in an Alaskan mill regularly?

 

[jmssaws]

My 084 is at .020 and is tuned around 14000, just tore it down to have a gander and it's fine, big chamber though. My 064-066 has bn at .016 for a couple years of hard living and is fine, it also has insane compression and has no signs of detonating. I've had a pile of saws apart in the last 20 years and have only cn 1 that had bn detonating, it was a low hour ms460 that was stock, the same company had a bunch of them all purchased at the same time and it was the only one, not sure why maybe it had a little more ignition than the rest.

 

[jmssaws]

That said, there won't be a customers saw shipped that's less than .020
The squish band is cut on my saws like a lot of other people's and .020 may b 30 or 40 more psi than a stock cylinder.

 

[ncpete]

hey there everyone, I have a 3120 that had straight mix seizure and I've just spent the whole morning cleaning up the OEM cylinder, and thanks to a few guys on this forum who told me its most likely salvageable, turns out I think it is!!! Yay.
The cylinder has cleaned up real nice.
I'm now going to order a new OEM piston and rings.
Anyways my question is what is a safe squish in one of these saws for a "work" saw.
I just measured it and I have 40 thou squish with the origanal piston ( I will re measure it with the new piston)
The base gasket is 26 thou, so by tossing the gasket I will be left with 14 thou which I think will be to tight? Right?
Where I work I have accsess to shim material (brass or steel) and I was thinking maybe a 7 thou base gasket might be ideal to bring the overall squish to 21 thou...
Would this be ok?