49 TO20 woes wont reach full rpms

So I'm new to tractors but am not new to carburetor engines. So I got this tractor for next to nothing and it was a basket case. First thing I did was a compression test, all cylinders were over 100psi. So started working on it carb was stripped cleaned and rebuilt. Set to factory settings, and replaced points, condenser, wires, plugs, fuel screen, and wiring. So now to the fun, it cranks and runs! Just not correctly, if I completely disconnect governor and pull throttle all the eay open it doesn't rev high like it should. The governor does pull back on the throttle when all hooked up. I have set the timing to factory settings and tried to mess with it to get it correct but no luck. Any idea where to start? I have not replaced the manifold gasket nor have I checked the valves but there is no valve noise. If they where to tight I would think the compression would be low, I have sprayed carb cleaner on the manifold to see if there is a change like a intake leak. Just agrivated with it, cranks right up every time, but even at 1500rpms it will drop for no reason then pick back up. Cant start of in 3rd gear, and using an impliment with it just isn't going to happen right now.

Pull the distributor cap of and make sure there is some movement on the rotor, about 1/8”. No movement, no advance and won’t rev up correctly. You could first start with the carb settings though. Seems like idle is okay, so open the big knob screw 1/2 turn and see if it makes a difference. That is the power jet. It should be at 1-3/8 turns open roughly.

Hey and thanks for the response. The rotor does move check that first. I have reset the carb a few times and it hasn’t made a difference. Normally something like this would point to either timing or carb but I can’t find an issue with either.

Cute toy.
3 fuel filters on your machine are the stand pipe in the tank, the screen inside the bowl and the brass elbow going into the carb also has a screen inside of it.
Tell ya' what.
Grab a can of starting fluid. Remove intake hose. Fire it off and rev it up. Now give it a shot of fluid. Did it rev higher? I suspect Fuel starvation. Slowing down might tell me you have a timing problem.
Congrats! Your diagnosed.
Now go fix it.

Check your points gap and condition, check the distributor shaft for side play. It must be tight or the points will not stay set.

Check the fuel delivery. Have a clean glass ready, remove the drain plug in the bottom of the carb, catch the flow of gas. It should have a full stream, not slow to a drip or stop. Look at what was caught, look for water or contamination. Unless the tank has been replaced or cleaned, at this age good chance it is flaking rust and near the end of it's usefulness. If there is an inline filter, that can be the problem. They don't work well with gravity systems.

What is the main jet set at? About 2 turns off the seat is a good start. Try opening it up a bit. To set it, once you get it running, open the throttle quickly. It should take throttle without hesitation. Slowly lean it until it hesitates, then back the adjustment out, repeating the test until it will take sudden throttle from idle without hesitation.

To check the governor action, engine off, dash lever to fast, the carb throttle plate should be wide open. Return the dash lever to idle, it should hold the throttle against the idle stop.

There is a wire mesh filter up inside the air cleaner. It is often overlooked and can be packed with dirt. If it's severely packed the mesh will have to come out and be cleaned or replaced. Try a test run with the air cleaner disconnected.

Someone correct me if I'm wrong, but just because you can turn the distributor shaft doesn't mean the fly weights aren't gummed up and stuck.

The fuel runs out of the drain quick. The fuel system has been cleaned, even the fuel tank before I installed it. Have even ran it at idle and cleaned the fuel bowl several times. No inline filter on it.

The main jet was set at 1 7/8 turn and there is no full rev, but seems to get there fairly quickly but not fast enough. Adjusting the jet out didn't make much of a difference there but did cause it to run rich.

Governor does try to shut the throttle, although I'm learning about them not too familiar. The throttle does not shut all of the way right now, this is due to me making sure that it was full throttle and still having to fix the throttle adjustment so it shuts all the way. It is not far from the stop plate thought.

The Oil bath cleaner has been completely taken apart and cleaned. I soaked the metal mesh in cleaner for a while most of the build up fell off and was bare metal wire. I have not tried running it without the air cleaner though, had issues that I just fixed someone had removed the mesh filter inside the eblow going into the carb. This tractor was a complete basket case and was missing a ton of parts so been one hell of a learning curve.

You are correct, but it didn't look bad inside. I have rebuilt some VW distributors, and it feels like the tension on the shaft moving is correct but wouldn't be a bad idea to take it down and start over with it.

A couple things left to check.

I hear it's possible to install the venturi upside down, not sure how it would fit, but might be worth checking, also the emulsion tube, be sure it is in and not broken off. Double check the float level. The specs are available online.

Another long shot, a restricted exhaust. Especially if it's been stored a while, critters stash acorns inside. Same for the air cleaner, even though it was apart they may have been in there since.

On the governor, the length of the rod from the gov arm to the throttle shaft is critical. To set the length, pull the pin from the clevis. Push the throttle plate closed against the idle stop. Note the position (length) of the rod with the throttle closed. With the clevis still disconnected, have an assistant start the engine, because you are in control of the speed. Watch that belt! Set the dash lever about 1/3 fast, Bring the RPM up until the gov arm stops moving back, note that position in your mind. Adjust the clevis until that position matches the idle position of the rod. The governor has to be able to push the throttle fully closed. To set the max RPM, set the dash lever to full fast, loosen the U bolt up above, set the gov spring to hold the RPM, about 2200.
Adjust the upper linkage so the throttle is pushed closed at idle, don't change the length of the previously adjusted rod clevis.

Of course you will have to get it running reliably before adjusting the governor.

Hope this helps!