TO-20 ruff running and no throttle control

demongo1129

New User
so i need some help here, been fighting with this tractor for a few months now. been through complete carb rebuild, intake/exhaust manifold cleaning and resurfacing, new spark plugs, re timed entire engine, tested compression, and went through resetting governor and throttle linkage. no matter what i get the same result, tractor is hard to start, runs ruff and the throttle lever does nothing to the engine rmp and then it dies out. it is easier to start when cold, harder when hot.
compression when cold was 100psi on cylinder 1 and 4, 90psi on 2 and 3. could use any advise on what could be wrong
 
Ignition points that are making poor contact or a distributor shaft bearing that is worn can cause those symptoms.
 
Governor action is what? Missing any springs? "and then it dies out" plugged fuel line? Especially in the elbow to carb, plugged fuel cap? Have you tried it with the gas cap of the tank? Any after market in line fuel filters you added? When it does, does it fire on ether?
 
Start with checking the points condition and gap. Check the distributor shaft for side play. It needs to have minimal movement, any wear and the points will not stay set. That can cause strange things, loss of spark at various RPM and temperatures.

Check the spark quality at the plug end of each wire. It should give a 1/4" blue hot spark to ground.

Pull the drain plug in the bottom of the carb bowl with the fuel valve open, engine off. be ready to catch the flow in a clean glass. It should give a full flow, not stop flowing or slow to a drip. If it doesn't have good flow, check the screen in the carb inlet fitting, the sediment bowl, and inside the tank. Be sure the cap is vented. Try loosening the cap even if it says vented, it may be clogged. If there is an inline filter, that may be part of the problem. They don't work well with gravity systems.

Look at what was caught in the glass. If water on the bottom, or trash and rust came out, the tank is contaminated, and the same will be in the carb, even though it was recently cleaned. The tank will need to come off and be cleaned, and the carb may need to be eased apart and cleaned out.

As for the governor, engine off, dash lever at fast, look at the throttle shaft on the carb. It should be spring loaded to the full open position. Then with the dash lever in the idle position, the throttle should be held closed against the idle stop.

If that is not happening, there is a problem with the governor linkage adjustment. Let us know and we can walk you through the adjustment.
 

How do I tell if it's something with the distributor, just replaced Sparks, spark wires, distributor cap, and rotor.
 

Two possibles I can think of both to do with air leaks .
The manifolds have been cleaned and I assume you have used a new gasket , were the mating surfaces ground flat at the time ?
An air induction leak will cause harder starting and rough running , getting worse as the manifold heats up and the gap increases .
Same goes for the carburettor to manifold flange , I know the Zenith 24T carb is easily warped if it's tightened too hard .
While the engine is running spray some WD40 or other such stuff around the joints . If it speeds up even just a little you've found the problem .
 
It has the marvel tsx-361x carb, which I
rebuilt, no change so I switched with a
new carb and still no change. I did
clean up the mating surfaces for the
manifold and new gasket. But now I'm
second guessing myself if I got the
manifold truly flat. I've replaced
almost everything except the manifold
itself and the distributor, I'm gonna
try checking the manifold again and
probably get a new distributor next.
 

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