IH 300 Utility

All,
I need help. I just bought a 56 model IH 300 utility. I think I am going to love the tractor as it has been nearly 100% restored and I recall working with one as a kid growing up. My problem is that the engine stumbles then labors and ultimately quits under load. I have driven short distances and within an eighth of a mile even on level road travel it also does it. Pulling out the choke helps initially but within a minute or two even that seems to fail and the engines goes into an eratic idle until it dies. Tractor restarts easy but I can't get any work out of it this way.
Need help pasture needs trimmed

Replace coil, cap, points, plugs and wires. The ignition is pretty touchy on those 300u tractors.

Three components affect the engine: Fuel compression and correctly timed spark.
The symptom as described shines on fuel as the first issue to check. Shut off the fuel at the bottom of the tank/sediment bowl. Remove the fuel line at the carburetor. It is a compound fitting and has a strainer in it at the fitting Do not use poor tools, use wrenches that fit and if necessary a Line wrench (looks like a C with the ability to touch the nut with many points of contact) When it is off, look at that screen if plugged, clean it)
Put a clean 2# coffee can under the line and turn on the fuel. It should run out in a PEE stream and do so for at least 2 minutes. If not the line, sediment bowl, or tank supply pipe is plugged. This symptom allows only enough fuel to get to the carb for partial replacement of the fuel used. If it sis for 10 minutes the carb will be full. It will run till the fuel begins to lower in the carb, then start to miss and choking just adds what little gas remains in the carb for a brief burst of running before stopping. The pipe leading to the tank can be the source of grief, it is necessary to drain the tank to get at it (obviously slowly as the line may be plugged pretty badly)
The second issue is a failing coil. These will be hotter than a fire cracker, and are internally shorted and cause very similar issues.
Check for spark immediately when it quits if no spark, there it is. Put a spare plug on a plug wire and ground the base of the plug, and watch it as someone cranks the engine (neutral brakes on). Shade or darkness helps see the spark. Bright blue and crisp is desired. Yellow and thready is bad.
Fuel first, then coil.
Compression is good or it would not run well at all. Jim

Jim's advise is good. Also look for an intake manifold leak. Easiest way is to blow some propane around the manifold. The engine will rev up when you're near a leak. This can cause the engine to run too lean, and can get worse when the manifold expands with heat.

Lack of fuel, what he said