TO-35 Stalling Under Load

I've done some work on my TO-35 lately. Rebuilt the crab, new cork spacer in the throttle linkage, new battery cables and spark plugs. Before doing this work. The tractor was having no problems running under load. The crab was flooding and the there was a lot of slop in the throttle. I had to take most of the throttle linkage apart to get the new cork spacer installed and it toke some tuning of the governess bumper screw to get the engine from over revving. The tractor will move in low gear but will stall if we give it more then half throttle. We cannot get it into high gear without the tractor stalling. I have not touched the timing so I don't think that is the issue.

As the load increases, the throttle opens farther. That lets the cylinder get more air/fuel so the pressure in it goes up. Higher pressure requires higher voltage to make the spark jump the plug gap. It may be that you need a new set of points.

That crab was dumping enough fuel to cover up the problem. It could be a bad point gap/burnt points/weak coil/ You leaned it out it now has less fuel in the cylinder and the ign sys has to work harder to jump the air gap.
Maybe the crab just needs new pinchers.
Take it back to the ocean and throw it in. It might live. . .
No? Too far? Okay. Local salt water tank.
Unless it's a fresh water crab.
I am sure you can figure it out.

Sounds like there may be more than one problem.

Everything works together. If the engine is sick, low on compression, valves out of adjustment, air cleaner clogged (including the mesh inside the canister), then it's not going to run right. Save the carb and governor adjustment for last.

First, check the points gap, check the distributor shaft for side play. It needs to have very little movement or the points won't stay set. Check the centrifugal advance, thr rotor should turn a few degrees CCW and spring back when released.

Check the quality of the spark at each plug wire. check each wire at the plug end, it should jump 1/4" blue hot spark to ground.

Then check the fuel supply. Have a clean glass ready, fuel valve open, engine off, remove the drain plug from the carb. It should give a full flow, slow to a stream, but not to a drip or stop. If insufficient flow, trace the problem back toward the tank. There is a screen in the inlet elbow of the carb, and one inside the tank. If there is an inline filter it may be too restrictive.

Look at what was caught in the glass. If cloudy, or water in the bottom, the fuel is contaminated with water. If dirty or rust chunks, the tank will need to come off and be cleaned or replaced if severely rusted.

Sinse the governor is probably out of adjustment, you'll need to manually take control of the throttle for the carb adjustment. Set the dash lever so you can manually move the throttle shaft from idle to full open. If that is not possible, remove the pin from the governor arm so you can operate the throttle.

Best to have a helper operating the starter and standing by to kill the engine in case the RPM gets away!

The engine needs to be fully warm with a working thermostat in place. Hold the throttle shut against the idle stop screw. Adjust the idle down to around 450-500 RPM, no higher. Adjust the idle mixture screw (the small screw up top). Turning the screw in richens the mix, out leans it. The screw adjusts air bleed, not fuel. Turn it to best idle then slightly in. If it has no effect, the RPM is too high, the idle jet is clogged, the throttle plate is not centered in the bore or in backward (important detail if it was removed). Get the idle to adjust before going any further.

Then adjust the main. Backing the main out richens it. Start about 2 turns off the seat. With the engine at idle fully open the throttle for just an instant, then return it to idle. Listen to the response. If the engine takes throttle without hesitating, turn the main in 1/4 turn, repeat the test until it wants to die under quick throttle. Then start backing the screw out as you repeat the test. The goal is to get it to take full sudden throttle without hesitation. No need to demonstrate high RPM, just the response as the speed is coming up. A single puff of black smoke is the goal.

Now, to the governor adjustment...

It is almost certain the governor is out of adjustment. The "bumper screw" is not for setting the engine speed. In fact, it is best left backed out and not touching the arm inside. You want all the governor stroke you can get.

Attached is a step by step procedure for adjusting the governor. Follow it closely, familiarize yourself with the name of each component. I would either print off the download, or carry the laptop out so you can have it through the process.

If you get stuck, post back, we can walk you through it.
TO Governor Adjustment

Hello, They used that carb on many engines,1-2-4-6 cylinder,And each requires a different kit, as the kit determines how much fuel they get.I,ve seen this happen many
times, Put the hi speed jet from the original parts back in and it will be fine ( the tube in the middle of the throat).....You put one in for a smaller engine and can't
get enough fuel, If you threw the old one away, drill the new one out a little at a time till it gets enough fuel...Ed-to35 owner 36 yrs.

Had to overhaul mine as liner rotted out and put coolant in oil

64yrs. old and still getting the job done.....