Stuck Rings or Wear?

I think your on the right track, Seafoam would be the first thing I would do. It’s my mechanic in a bottle and I just put some in my new to me D14 today. Tractor has been sitting for a while and even though it runs good, no smoke, I always clean them out good when I pick up something new. Ironically, I run Shell Rotella 15W-40 in all my tractors and just picked some up today when I changed the oil and added Seafoam. Good luck, hope that takes care of your issue. Make sure you run it for awhile to allow it to do its magic. It sure has resolved issues in the past for me, be prepared for the oil to be jet black. A result of cleaning all the carbon up.

MMO already has some kero in, which things it out Honestly costs about the same as ATF anymore. Might just wash the junk down to the pan with some of that cheapo Providence oil RK has.

just run it and monitor oil usage.

+1 one the seafoam, but don't run it in only the crankcase or fuel and expect it to do much. The best results I have are from using their 'Deep Creep' penetrating oil (or similar) directly in the cylinders. Pull the plugs, spray a decent amount in each plug hole, crank the engine over for a second or two with the plugs out just to splash it all around and coat the valve seats (some will get shot out the plug holes), then spray a heck of a lot more into each plug hole and let it sit for a few days to soak into and break up all the carbon/gum deposits. Repeat after three or four days, then fire up and run hard. It's amazing how much carbon that can clean up and how much smoother the valve action can be made. It'll be smoking and coughing for a while after you do this treatment, but once it pukes all the gunk out it can make an incredible difference on how it runs and how much blowby/compression you have. Even better than the 'Deep Creep' is the Delco penetrating fluid that GM dealers sell - that stuff cuts through everything. I also like to pull the valve cover off and coat all the rocker action and stems in penetrating oil and let it sit for a few days, because often valve sticking and low compression is from crapulence built up or caked on the stems/guides.

Edited by DanielW - 15 hours 41 minutes ago at 9:43am

Yeah, soaking the pistons and valve seats helps break up carbon in the combustion chamber, clean up the valve seats, and allows it to percolate into all the ring grooves and free up the rings (and break up any carbon in the ring grooves). Soaking the valve stems from the top is perhaps even more important, as sticky valves due to gunk on the stems is such a common problem.

Edited by DanielW - 13 hours 52 minutes ago at 11:32am

New symptom. I added seafoam to both the fuel and oil, as well as dumping out the sediment bowl and refilling it with seafoam. After running for awhile and driving around at PTO speed (no real load, but with the PTO shaft and belt pulley running), it developed a bit of a miss, which is where I'm assuming the miss from cylinder #4 came from before. It didn't seem to smoke as much as it did yesterday, but if at full throttle or PTO speed, there's no smoke. It's pretty much just at idle/high idle and when increasing engine speed or loading the engine, like when taking off from a stop. 

Edited by Clayfoot - 5 hours 2 minutes ago at 8:22pm