Compression Problem on 190 gas that's been sitting

This tractor supposedly ran OK when it they parked it 10 years ago...and it did have antifreeze in it the entire time. As of this morning, it didn't have much/any compression on 5 of the 6 cylinders. After pulling the valve cover, we could see that the intake valve on those 5 cylinders was sticking down, and then veeeerrrrry slowly rising back up. The push rods on two cylinders we not even under the tappets any more.

After lots of WD40 and prying back up on the valve springs, we appeared to be in business as all the valves now appear to be working quite smoothly....until I went around and did a quick compression test with my finger over the spark plug holes. Two of the cylinders still have no compression. Looking through the spark plug hole, the pistons do appear to be going up & down.

I'm just looking for your best guesses on the cause, based on the history of it sitting. I'm just not sure what things would usually cause low compression vs. no compression...and this sure appears to be NO compression to me. If the rings were just worn, I would guess low compression. The only other things I can think of are bad head gasket, cracked head, bad valves and/or seats, cracked block, bad/broken pistons.

I'm really not looking forward to tearing it down, but it looks like that's where we're heading.

Thanks.

�Dump a Quart of Oil down the M()!%#%*#^+KER .�

I couldn�t believe what I had just been told�engines burn gasoline, not oil.

I said, �What�

He repeated,� �Dump a Quart of Oil down the M()!%#%*#^+KER .�

I needed an explanation, and eventually I understood�. I was to take a one-quart container of regular crankcase oil and slowly pour it into the carburetor with the throttle partly open while cranking the engine with the starter. Surprise, doing so increased the compression from the additional sealing effect of the oil and the engine started long before I�d finished pouring the entire quart into the carburetor. When the oil smoke had cleared we had a smooth running engine!

What had happened is the engine had become �dry� from sitting such a long time. When we wanted to start it we primed it by dumping gasoline down the carburetor and that washed what little oil was on the cylinder walls away. Engines depend on oil for its sealing effect as well as cooling and lubrication.

I went back to the guy who gave me the advice

and told him, �The M()!%#%*#^+KER� started!�

He knew it would. That was the last time that engine ever gave us any compression problems because after it had been run awhile the normal amounts of oil inside the engine sealed the cylinders.

The result???? In this case it came out the exhaust stack. We did some more playing around with that valve (just lubricating it and prying it back up as we turned the motor over), and got some compression pretty quickly. We shot a little starting fluid in each cylinder, spun her over, and listened to her slowly come out of retirement. Once she blew all the cobs out, she actually ran pretty good. We still have some more work to do, but it's good to know that a teardown hopefully isn't necessary. We can't get it to run very well without it being partially choked, and a couple of the push rods appear to be a little bent that will need replaced (which I assume we did when we first tried to turn it over not knowing some of valves were stuck.)