Got me a 1950 Harry Ferguson last week.

[Twisted_Steel]

I drove it around some, greased all the fittings and checked the compression. Cylinders 2,3,4 had 110psi. Cylinder #1 had 35psi. Not good
Checked the cylinder with my bore scope and it has a lot of carbon buildup. I'm hoping the carbon is not letting the valves seat completely. I got a bottle of Sea Foam, poured some in the tank. Tried starting it and smelled wires cooking. My ballast resistor has fried. 12 volts from the switch and only 3 volts out the other side. I ordered a couple and they'll be here tomorrow. Hopefully it'll fire right up after swapping it out.
Here's a pic of ol' Gus when I got it home on the trailer.

 

[Ray,IN]

In the 1950's my uncle owned and operated a filling station and did mechanical work. when he suspected a carboned-up valve was not sealing properly, he used a fixture that was made by GumOut. It replaced the gas line inlet in the carburetor and fed liquid GumOut directly into the carb.
GumOut quit making that fixture so he figured out something else. He would control the flow out of the can with his thumb and trickle GumOut into the carb enough to just keep the engine running. After ½ can remained, he dumped it suddenly into the carb, which stalled the engine. He let the engine sit overnight, then started it next day. The engine would smoke, run very rough for about 3 minutes then smooth out.
Then measure compression again. If the numbers were not up to spec he'd repeat the GumOut thing. He sure saved customers a lot of money quite often, with that "trick".
About 1992 I did that to the Dodge V8 in my 1976 Allegro motor home. I was pleasantly surprised it worked to clean up the valves. (backfiring out the exhaust and blowing manifold gaskets was the problem) I was really dreading tearing that engine down, working from inside the MH.
That works with a carburetor, and I suspect will also work with a TBI engine.

 

[Twisted_Steel]

I can't get her to fire yet. So the Sea Foam is just sitting in the tank

 

[TimothyF]

Clean out the canister air filter mesh and add new oil to it. Clean the gas filter screen. Check if there is a little screen inside the carb entrance. Do an oil change with a can of BG EPR. Consider upgrading to a Pertronix electronic ignition at some point. Don't use the tractor without an over running coupler. Enjoy!