I ran into this by accident. Cleaning up from some minor flood events (before Christmas) and getting to the machines that did not make it out (after Christmas) - I finally got to the roto-tiller. Uses a single cylinder Briggs. So I pulled the plug and drained the oil/water. Filled the crankcase with WD40 and sprayed a big slug of BreakFree into the cylinder. Let it sit for a day and fired it off for a few minutes. Drained it all and put in new oil. Got the water out of the gas tank and started it for real.
Compression was always weak on this motor. Very easy to pull over. Ran OK once started, but no real power. Anyway after the flood cleaning, compression is noticeably higher. You can really feel it on pull over. Starts much “snappier”. Ran it around the veggie garden plot in seriously wet dirt that would usually bog it down. Just ran on and on
So then I went to do a chainsaw that I though might have gotten damp too … Only did the BreakFree from the plug hole and a little in the carb. No WD40. Bingo, again more compression and seems like more power.
So it seems that BreakFree can actually loosen stuck rings. Never thought of it that way before, but there it is. I’m going to try it on the 1988 Big Bronco with 200K +. See if it helps with at least top ring freedom. Maybe it’ll help, maybe not … But seems to be possible?