Governor Linkage Moves on 1 side but not the other..??

I noticed today on my little Cub that the engine runs at about 1/2 throttle, and will not idle any lower with the speed lever all the way back. As I worked the speed lever from about 3/4 throttle position to idle position; I noticed that the linkage going to governor worked and moved the lever on the governor back and forth by use of the spring that is visible on the outer part of the governor housing. Ok, seems to be fine. When I looked at the governor linkage/rockshaft on the carburetor side of the tractor, I noticed that the rockshaft and linkage DID NOT MOVE AT ALL!!

To me it seems as if there is some small "connecting part" within the governor housing and governor rockshaft that is broken or loose. That is just my guess, as I really am not sure.

I would love to have everyone's opinion and help on this before I take the governor off and replace the whole unit. It might be something simple to fix like a keyway or bolt or something....

The governor has worn internal parts and/or the linkage between the governor and carburetor needs adjusting.

If you are not experienced in this area, finding someone who is COULD save you some $$$ for unneeded parts.

You are EXACTLY RIGHT Bob. We were talking today about that. We've never diagnosed and rebuilt a governor ourselves, and need to find someone who is good at it at a reasonable price having that they are a costly part to fix. For this tractor, I think we will just replace it with a good (hopefully) used governor off of a parts tractor. I already have around 4 or 5 governors that need fixing though, and need to find someone that does that.

Question: If I take the carburetor off (I am going to install a freshly re-built one); should the rockshaft/linkage that goes to the carburetor move back and forth when I move the engine speed control at the operators platform. I mean, does it move back and forth when I advance/retard the throttle control while it isn't hooked to the carburetor.

The reason I asked that, is because if it does not move for me, and is supposed to; then there is DEFINITELY something inside the govenror that is broken.

My first job though is to install a fresh carburetor and see what happens.

The spring inside the governor fights the action of the weights to control speed. Without the engine running, half of this equation is missing... the action of the weights that tends to close the butterfly as engine speed increases.

For someone familiar with setting up the linkage or verifying if the governor is functioning, it would take FAR less time "hands on" than to try to explain the whole procedure in writing.

BEFORE buying parts or tearing into anything, have a knowledgeable person check it out or obtain a copy of a shop manual and begin by following the procedure to set up the linkage between the governor and the carburetor.

(quoted from post at 23:59:54 04/02/11)
Question: should the rockshaft/linkage that goes to the carburetor move back and forth when I move the engine speed control at the operators platform. I mean, does it move back and forth when I advance/retard the throttle control while it isn't hooked to the carburetor.

Click to expand...

It usually does, but if the governor is not set correctly it won't. There are several conditions that can cause these symptoms. I wouldn't jump on any assumptions. Here are a few diagnostics:

[b:4dd773711b]The governor travel adjustment screws are too tight.[/b:4dd773711b]
The governor screw adjusts the maximum mechanical travel to keep from damaging the carburator. But if adjusted too tight, it can keep the carb linkage from moving sufficiently. Too loose and it can damage the carburator. With the engine "off", remove the rockshaft bracket and shaft. Do not lose the key on the end of the shaft when the shaft is pulled out of the governor. Use a flashlight and watch carefully. Back out the screws and count the number of turns while watching the governor cross shaft keyway for rotation. If there is rotation continue backing the screw out until the rotation stops. Set the governor throttle control up by the steering wheel to the idle position. [b:4dd773711b]"CAREFULLY"[/b:4dd773711b] start the engine and [b:4dd773711b]manually[/b:4dd773711b] control the engine RPM with the throttle on the side of the carburator. Do NOT allow the engine RPM to high rev, keep it at a slow Idle. With a flashlight, watch the governor cross shaft socket on the side of the governor. Slowly increase the engine RPM and watch to see if the governor rotates clockwise in an attempt to close the carb throttle. If this is working, the governor is NOT the problem. Set the travel adjustment screw to just a little less than the travel needed for the carburator open-to-close travel needed. With the engine off, set the carb control rod length to fully open the throttle. Now when the engine starts, the governor will close the throttle to the idle RPM.

[b:4dd773711b]The rockshaft linkage to the carburator may be adjusted too short. [/b:4dd773711b]
This assumes that the governor maximum travel screw is adjusted properly (i.e. control shaft moves back and forth just enough to open and close the throttle). With the engine "off", adjust the carb linkage out enough to open the throttle wide open. As the engine starts and begins to rotate the governor weights, they will pull the rod and try to slow the engine down. Moving the throttle applies extra force to counter the force of the weights to allow the engine to increase in RPM.

[b:4dd773711b]The governor rockshaft keyway has too much slop.[/b:4dd773711b]
With the engine "off", Disconnect the control rod from the carburator. Gently rotate the rockshaft back and forth while using a flashlight to observe the insertion point into the governor keyed opening. If there is significant slop, unbolt the rockshaft assembly and simply pull the shaft out of the governor (do not lose the shaft key). Look for damage. You can replace the key stock if deformed, beef up the keyway with shim stock like a piece of hacksaw blade, or use locktight if the slop is excessive. You can break the bond of the locktight in the future by heating the shaft up with a torch. Be sure to use the rockshaft bracket in its final bolted position to align the shaft before the locktight sets up. Recalibrate the governor system since there will no longer be any slop.

[b:4dd773711b]External spring and control arm on governor that connects to the throttle by the steering wheel is frozen.[/b:4dd773711b]
Rust can cause the control arm to freeze up and so the throttle input does not cause a change in RPM. Use penetrating oil and loosen up the throttle input assembly until it rotates smoothly under the spring pressure. Apply some grease to keep the assembly lubed.

Only if the travel screw adjustments allow for maximum movement, AND the throttle input assembly moves freely, AND a change in RPM (slow idle to mid RPM) does NOT cause a governor rotation with the cross shaft disconnected, would I consider the rebuild of a governor.

A piece of advice: Don't instantly start throwing parts at, or start searching for someone to pay to rebuild, something you PERCEIVE as "broken."

Mechanics just drool like hungry wolves over people like that. They know they can soak people like that for big $$$ and not even feel bad about it, because the customer is coming to them and asking them to do it!

A lot of times, the output shaft of the governor will seize up on these Cubs from exposure to the elements and lack of use. All it takes is a little Kroil or PB Blaster and some elbow grease. A mechanic would charge you $75 for 5 minutes of his time and three cents worth of Kroil!