grandpa Love

Well-known Member
This past summer at a tractor show we
were told the governor wasn't working on
our '39 B. What's involved with fixing
it?
Tractor runs great but going up hill you have to add throttle.
 
Hard to say till you open it up. Could be as simple as needing new springs or could be as bad as needing a lot of other parts. Only way to know for sure is trouble shoot things a bit.
 
Contrary to what many guys think, the governor spring (rather than the governor) acts to open the throttle, and the action of the governor is to FIGHT that force to prevent overspeeding.

The governor doesn't by itself open the throttle in response to load, it actually "backs off" and allows the governor spring to do that.

The most COMMON cause of a "lazy governor" is an engine that's "out of tune", suffers from restricted fuel flow or late ignition timing and/or a bad spark advance mechanism.

But first, check to be sure there's no binding in the governor-to-carburetor linkage system.
 
Assuming all the parts and linkages are there and correctly assembled the two most common causes of that on a B are the fork on the governor arm gets worn and or bent or the governor weight pins wear out and break. Which it could be depends on the exact symptoms. If the governor does not work at slower RPMs and light loads but seems to work when you advance the throttle to wide open and place a load on it then it is the former. If it never works and will overspeed if you advance the throttle with no load then suspect the weight pins and you got lucky as it often takes out the timing gears.
 
The most common problem with a dead governor (besides binding/sticking linkage) is the fact the governor arm and link rod are not synchronized to the carb arm. The length of the link rod is to be just long enough and not too short when the throttle is open and the link rod front is slid out of the cross arm. 1/8" of an inch incorrect makes a big difference in governor performance. Now, you say it is a 1939. If so, the governor linkage was poorly designed and was improved a year or so later. Yours might be either style. If your governor spring is small diameter ( 1/2" or less) you have the old poor performing governor. The newer parts have a larger diameter spring (3/4" or so) with a plunger inside of it. When they changed the spring design, the cross arm was changed also. The two go together and cannot be mixed with old parts. Proper adjustment of the linkage and the newer designed linkage and you will have a typical snappy AC governor.
 
Rather than look at a dozen maybes and try what ever you might like to think to try first, why not start with the linkage being in adjustment. That seems to be the last place people want to check.

Any time I personally had a governor problem on this type of governor setup I started by disconnecting the crossover arm linkage. I then go back to the steering wheel and push the gas lever full forward. I then walk all the way back to the front of the tractors left side and pull the carburetor linkage full forward. At that point I check to see if the linkage is dead on or 1/16" past the hole. If it is not the crossover arm needs bent until thy do line up as my picture shows. Make sure the crossover arm is not rubbing the water outlet.

When it is in adjustment and it still has a problem I then and only then would I look for other causes.

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