'49 Farmall Model C gov to carb adjust

mpbarber

Member
I've been working on this tractor on and off as I use it. (And having a great time!) I have an 89 Tempo, a 91 Ford CV and a 93 F150 and compared to those, it is a joy to work on this old tractor.

I R&R'd the carb and then tried to set the linkage between the carb throttle & the rockshaft arm. With full throttle position using the throttle lever and the carb connecting rod all the way back for WOT (wide open throttle), I removed the yoke pin and found that the pin "holes" missed each other by almost an inch.

The problem is that in order to line them up, I have to turn the yolk towards the carb and there isn't enough thread to go as far as required.

I can't imagine that it should be this far off without something else being wrong.

A couple of thoughts:

Can I loosen the rockshaft arm from the rockshaft and move it away from the carb to get the adjustment? From the diagram I have it looks like there's a pin or something that sets the relationship between the two. Unless it's been broken off.

If not; does this mean that the rockshaft lever inside the gov or the gov thrust sleeve and bearings may be bad?

All linkages work freely including the throttle plate at the carb and it "feels" like all the gov bearings/bushing are tight and the rockshaft/arm rotate to a solid stop in either direction.

Thanks in advance for any advice on this.

Oh yeah, it runs great other than a surge at idle which once I get the carb/gov linkage problem solved I'll check the bumper spring setting.
 
That linkage cannot be an inch wrong.
If the throttle hand lever when moved also moves the governor to carb lever, and the carb throttle lever on the carb is turned so it is wide open as well, the adjustment should be expected to be a half hole or so at most.
an inch is almost the entire travel of the rod.
Make sure the carb is held wide open, and the throttle hand lever is full fast position.
Jim
 
The arm is keyed to the shaft. If it runs fine, why are you messing with it? Surging may be a clogged idel passage in the carb.
 
Off the top of my head it sounds like you're pushing the throttle CLOSED, which would explain why you've got 1" of difference.

When you move the throttle lever from idle to full, watch which way the governor tries to move the throttle rod to the carburetor. When you adjust move the rod in the same direction.

BTW, if the throttle rod is out of adjustment, the surging will be totally uncontrollable, not just at idle.
 
mkirsch... Good point. I went back and I did do everything right. I took the time to actually measure the distance between the hole centers and it's right at 1/2 inch.

No surging other than at low speed. When I pull the throttle lever all the way back to slowest position it stalls.
 
teddy52food.... First, I'm a retired engineer so I can't help myself. Secondly, it was real hard to start, didn't seem to be running at top speed and would stall if I didn't "feather" the clutch.

I rebuilt the carb and that really didn't change much and there was no surge at that point which got me thinking about the gov/carb adjustment.

I cleaned the starter and that helped a little so I started checking all the wiring and grounds. I disconnected and cleaned all the connections to the voltage regulator and generator and I don't know why but that made a huge difference in how it started and ran.

That's when the low speed surge started.

So I thought I'd just check out the gov/carb linkage.
 
Jim.... You're right. I measured it and found it to be just under 1/2 inch.

As I mentioned in my other reply, I rechecked everything so I'm pretty sure I'm doing it right.

If I take up the misalignment it looks like I'll use all the thread on the carb rod.

Do you think I should do that and then try the low speed bumper adjustment or just go straight to the bumper adjustment?

thanks,
mike
 
I have the same problem with my Super C.I try to set it like everybody says but it just will not hook up right, I have tried everything.
 
If it is 1/2 inch off, someone has messed with it. Thread the rod more if it is too long, and cut off the extra. If it is too short, a new correct rod is in order.
Moving the throttle open is moving it in the direction that the rod moves when the throttle hand lever is moved from idle to fast.
When both are moved to that direction, measure and make the rod that length. Make sure it idles when the hand lever is moved to idle.
If it dies in the idle position, the idle speed (and or) mixture need attention to make it idle sweetly. Jim
 
Jimmy,

When you say you have the same problem, do you mean you don't have enough threads to move the yoke on the carb linkage to get the holes to line up?

mike
 
Jim, I'm pretty sure I got the throttle and carb linkage position figured out. I'm going to do 2 things;

1. I'm going to make sure the arm is in fact keyed to the rockshaft. It's that engineer thing.

2. Then I'll adjust the yoke and see if there are enough threads. If not, I'll make more threads as you suggested.

Why would anyone put the wrong carb linkage on? Rhetorical question of course.

thanks
 
Just a passing thought. Go around to the other side and take a look at the throttle shaft where it hooks up to the govenor. There is a tension spring on the end of the shaft that pins to the govenor arm. Make sure the spring is not rusted and stuck in one spot. I just finished completly rebuilding mine and there was all kinds of things wrong with it. It seemed to run fine before, but it runs alot better now.
 
When I set the throtle all the way up then hold the carb rod up to match the yoke to the gov.rock shaft I have to run the yoke all the way out to the end of the carb, rod to get it to match, then when I start it it will not idle down, it wants to run wide open,I have a manuel and have read every thing I can find on here, I have had the gov.of several times replaced thrust bearing, spring,little spring on the end of the gov. shaft.I am at my wits end. any ideas? thanks.
 
You are holding the carb rod backwards as its closed when you hold it like you are doing. If it dies when the hand throttle is closed just set the idle speed screw on the carb NOT the one for idle mixture. It is possible the lever on the throttle shaft where the linkage fastens has moved on the throttle shaft. I did have one carb where that lever was loose and another one where that lever had moved it needed a new throttle shaft in the carb.
 
Gene... I will look again to make sure about the carb rod and I did notice the difference between the idle speed and idle mixture screws. I'll check the throttle shaft in the carb also. Great tips.

Thanks,
mike
 
Rick..... That is one of the first things I checked. I made sure both springs were free and that the connector was free on the shaft. Added a few drops of oil for good measure.

thanks,
mike
 
Jimmy... Sounds like you have the opposite of my problem. It looks like I'm going to have to turn the yoke towards the carb.

I haven't taken the gov apart but I've read the instructions a couple of times and one of the things mentioned was making sure that the large spring was not only hooked in the correct hole on the rock shaft, there are 2, but also that it was facing the right way since apparently the hook can catch on something if it's put in "backwards".

Can you manually operate the gov from the carb side of the engine and get any control over the engine speed? That at least would tell you that the gov is not restricting the throttle movement.

Other than that, I'll defer to the other guys on here because it's clear to me that they know a lot more about this than I do.

good luck,
mike
 
gene.... I rechecked the linkage and I am holding/pushing the carb rod back towards the carb and with the throttle lever pushed fully toward the front of the tractor, which pushes the rockshaft arm toward the carb I get the 1/2 inch "overlap" between the alignment holes. I'll take another look at the rod to carb connection. I've had that carb off a couple of times.

thanks,
mike
 
the spring you mentioned comes with both hooks turned the same way, on my old one the hooks were turned opsite one another but they do not come that way now.
 

What does your manual tell you about that spring. Mine has a diagram showing the spring and the direction of the hooks. Does yours show 2 holes on the rockshaft lever? My diagram shows an "A" and a "B" and there is a chart showing what hole to use.
 

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