Minneapolis Moline RTU has little power

Bought a 1951ish MM RTU, was sitting outside for 10 years, did not run. Engine was free, took off carb, cleaned, filed points and it fired right up. I have changed all the fluids, hoses,
rewired, painted, etc. It will run and idle great, but it doesn't have a whole lot of power. Now I have a Massey Harris 30, Farmall H, John Deere MT and all of them seem to have
WAAAAAYYYY more power. If you are pulling just a running gear, no problem. I loaded a full 200 gallon water tank on it and it had a hard time getting around. It doesn't seem to want
to pull a load of any kind. I want to use her for mowing here and there as well as the occasional wagon pulling. Not sure what to do here. Governor is free and moves when under
load, but doesn't do much. Thoughts?

Check all the obvious, point gap, distributor shaft wear, centrifugal advance, ignition timing, plugs (I would go ahead and replace them), plug wires, cap, rotor.

Have you looked at the air filter? Be sure the mesh up inside the canister is clean, check for dirt dobbers and mouse nests.

Now that it's been run enough to get the rust off the valve seats, be a good idea to check the valve clearance.

To check the governor, set the dash lever to full speed. With the engine off, the throttle plate should be firmly against the wide open stop. If not, the governor is not fully opening the throttle. Adjust the length of the linkage between the gov and carb. This will not change the governed speed.

Have you adjusted the high speed mixture? Do this last after checking the above. With the engine running at full governed speed and fully up to temperature, hand close the throttle plate, let the engine idle down, then release the throttle. The governor should quickly open the throttle fully until the engine comes up to speed. Listen to the engine and watch the exhaust. If it stumbles on acceleration, back the main jet out about a 1/4 turn and try again. When it's right, it will take full throttle from idle without hesitation. A puff of black smoke is desirable. Continuous black smoke means it's too rich. You'll know when you hit the sweet spot!

Did you by chance get the firing order wrong when you changed things?? If you did they will run on 2 cylinder and the other 2 not be firing when they should and have a whole lot less power. Of if the point gap is wrong that messes with timing and causes odd problems. Or the air cleaner could be clogged up so did you change the oil in it?? Does choking it hurt or help?? If it helps it could see running to lean and that would cause lack of power. Or if it is running to rich and you have black smoke tha twill cause problems also.

Or it could be real low on compression. An engine that has sat a long time tends to have sticking rings which means low compression and that equals low power. I'd try a ATF treatment. Fill the cylinders with ATF and let ti sit a few days. Be sure to put the plug back in to keep dirt etc out. Then pull the plugs and spin it over to clear the cylinder and give it a try

Plugs are new, points are new, adjusted, new cap, new rotor, new wires. Air filter was torn down, soaked in a hot solvent tank for 3 days, cleaned, reassembled. I will try your throttle adjustment. What concerns me is that the engine starts right away. I rebuilt the starter, it is 12 volt now, rebuilt generator, all cylinders are around 150 psi, so I feel that the rings are free. Valves I left untouched since it ran nice. I am confident that the linkage could play a role. It was well worn and I re-bushed everything in the throttle and clutch departments with bronze.
One other thing I think I should have mentioned. The tractor had a BAD carb. The body and bowl were rusty as all get out. I used electrolysis to clean them, but the body was the only savable part. I used a Marvel bowl from a Massey that seems to fit just right. Is it possible that the bowl from the Massey has been jetted too low for the Moline? The other carb came off a Continental Z134.

Before and After.

Did you forget to put a venturi in it??????????????

There could be some jetting issues, but if it idles well, that's a good sign the carb is close to right.

There should be enough adjustment on the main jet to make either one work.

Did you use the MM venturi? It may be slightly larger since that is a larger engine.

Sometimes the governor linkage can be tricky to get right. Not familar with that exact model, but they all function the same. The governor spring wants to open the throttle, the spinning weights want to close the throttle. It's the balance between the 2 forces that make it work. Sometimes it's easier to take the throttle plate linkage loose, control the engine speed (be careful!) while you "feel" the governor working. That way you can see what the length of the rod needs to be to get the full travel on the throttle plate.

Check the air cleaner top cap, Our mud dobbers here in OK. like to build there nest in the cap. BTDT. Tractor will run lots better with out their nests. HTH. clint

Do a compression check on engine. If it sat for years could be issues there.

Plugs are new, points are new, adjusted, new cap, new rotor, new wires. Air filter was torn down, soaked in a hot solvent tank for 3 days, cleaned, reassembled. I will try your throttle adjustment. What concerns me is that the engine starts right away. I rebuilt the starter, it is 12 volt now, rebuilt generator, all cylinders are around 150 psi, so I feel that the rings are free. Valves I left untouched since it ran nice. I am confident that the linkage could play a role. It was well worn and I re-bushed everything in the throttle and clutch departments with bronze.
One other thing I think I should have mentioned. The tractor had a BAD carb. The body and bowl were rusty as all get out. I used electrolysis to clean them, but the body was the only savable part. I used a Marvel bowl from a Massey that seems to fit just right. Is it possible that the bowl from the Massey has been jetted too low for the Moline? The other carb came off a Continental Z134.

Is the governor reacting to load? I have one and the governor got real lazy.
Loren

Make sure that you have adequate fuel flow to the carb and that the air filter is not restricted. Both with limit power IF the engine is in reasonable mechanical shape. Also make sure that you have a good spark, the initial timing is correct and the centrifugal advance is working. Make sure the carb mixture is correct and the power jet is not restricted. If that all checks out make sure the valves are not sticking and you have adequate compression.

I will check, but I am pretty sure that I did put a venturi in. I can't remember which one it was.
It has plenty of fuel flow. Air cleaner is disconnected.

If you get really stumped, I do have some used carbs and governors in the shed. Sometimes starting over and bolting another one on is the easiest.