What a bummer...
I'm so close to finishing this project that I can see the light at the end of the tunnel. I still have some more of the slope to cut back and a little more leveling to do in front of and behind the barn, but the old girl is laying down me. Was out using it today and the blow-by smoke from the vent tube has gotten a lot heavier and just getting worse. After several hours today, the engine is now laboring to do what it was doing with ease when I started this project. I don't know if she's got enough life left in her to complete this project.
I pulled her into the barn and pulled the injectors to run a compression test. All three cylinders were reading about 300psi. Spec for this engine is 498 +/- 14psi with a low limit of 384psi. Not good. While I was at it, ran a leak-down test. All three cylinders were passing a considerable amount of air past the rings and No. 1 cylinder was also passing air past the exhaust valve.
I was planning on finishing this project up and then getting into the engine over the winter. Now, my plan is to mount the backhoe and open up a few places along the cut on the low side to allow water to drain out and prevent ponding. Then I'm going to take the tractor out of service and pull the head to take a look at things... re-ring and hone or bore and oversized pistons. The head will also get a valve job, guides, etc.