Got a stuck motor
 

My dad's Allis Chalmers D17 has been sitting outside for a few years at my place and now the motor is stuck. Last year I dumped some ATF/Acetone down the plug holes but it's still stuck. Tonight I pulled the starter and tried to use a pry bar on the ring gear to move it but got very little if any movement. I did spray some PB down the holes but I need to get some more acetone to go with my ATF.

What if anything have you guys & gals used with good luck on freeing up a stuck motor?

If you got it to move just a bit, that is a wonderful thing as it usually results on it freeing up.
Best to continue moving it both ways and not in the same direction as the back forth movement is much like a tapping operation, turning, then backing up to break the chip.

Bad news is is the engine usually needs to come apart to fix it correctly.
Most times it sets up because water gets into one or more cylinders and that is a bad things that gets worse.
Kroil works well, as does diesel fuel, or 16 to 1, 2 stroke mix. But normally most any penetrating oil works.
I have seen situations where I close the valves (loosing the rocker arms)
then pump a cylinder full of hydraulic oil and using a port-a-power or hydraulics of another tractor to push a piston down,
connecting it through the spark plug hole.
Just some ideas to help.
Oh, and think positive that honestly helps!:beerchug:

My Dad had a stuck 8N from sitting outside a long time. Managed to free the motor using mystery oil and pry bars. We got it to run, but the gas Ford was big time smoker. Rings were stuck in the piston grooves and cylinder walls were damaged from rust. We were able to do a rebuild with a kit and new sleeves.