White Lightning  Easy Clean Bicycle airical spray chain cleaner ,from Walmart
a while back j picked up a can of this stuff and put it on the shelf
last night i stripped down an OS LA 25 that hadnt been run in about 3 years and was totally gummed up

the rod was stuck to the wrist pin and the wrist pin was stuck in the piston.  the crank didn't want to come out of the case .after spraying everything down ,everything freed up and came apart with no problems.just sliding the rod back and fourth a couple of yimes and it was totally free  washed all the parts in Dawn and oiled everything before re assembling ,it now feels like a new engine.

the only drawback is the smell

Bob,
Get out the heat gun, take off the backplate and head, warm the whole thing for a few minutes then let it heat soak and heat again (especially the wrist pin). I have done this on the a K&B 40 that sat for 10 years, worked better than the crock pot.

See you Sunday at the Airstormers contest.

Best,        DennisT