I started soaking them with Zep 505. Then hit again with Zep and a scotch brite pad. The tough stuff got the brass/wire wheel treatment followed by Zep and the pad. Then I hit the outside of the cylinders with the shop vac to try to keep the gyrotis from getting past the upper ring and/or into the pan. I'll be swapping oil after I get it running anyway, let it run long enough to hopefully let the filter catch whatever made it into the oil system.
