Governor to carburetor linkage length.

[fiddler]

So the governor to throttle linkage on my 48 cub was so rusted and bent that the adjustment was impossible. I bought a new rod. This rod is longer than what I took off. Too long in fact to install when the governor is put into the wide open position for alignment. I think the reason the old one was bent is maybe it came off of another farmall tractor? Has anybody else seen this?? Did I just get the wrong part?? Thanks for any inputs...

[Bob McCarty]

How long is yours? I measured one at 10 3/4" for the rod only. Could you cut some more threads and cut off the extra length?

[fiddler]

Thanks.. I will check the length and yes..I can cut and I have a die set. I may have to buy the right size from ACE. Thanks for the measurement. Much appreciated...

[fiddler]

My new one is 10 3/4 as well. My old one is skewed around to where it is only 10. I wonder if someone tweaked the rod on the governor. I think I will try to determine the angle of the connecting rod when the throttle is placed to wide open on another cub and compare it to mine.

[fiddler]

OK re re re reading the adjustment procedure maybe I need to adjust the top bolt on the governor to allow the connecting rod to move further towards the radiator.....

[fiddler]

This governor was missing parts and the carburetor was attached direct to the throttle control so lots could be mal adjusted and just broken...

[Glen]

Hi,
Below are pics of the rod and yoke from TM Tractor.
It is important that the rod and yoke be the right length.
The governor won't work right if the position of the yoke on the rod is not set close to exactly right, making the rod with it's yoke the right length.

http://www.tmtractor.com/tm-tractor/ggv ... od_001.htm

Below are TM Tractor's pics of the shaft that goes across the front of the engine, and the bracket that bolts on the engine.

http://www.tmtractor.com/tm-tractor/ggv ... n1_001.htm

Below are pages from the Cub parts manual showing the governor and linkages.

http://www.farmallcub.info/manuals/cub_ ... 012-18.jpg

http://www.farmallcub.info/manuals/cub_ ... 012-19.jpg

The bolt at the top of the governor is the high speed limit adjustment bolt. Turning it up lets the throttle lever go ahead farther, increasing the speed of the engine.
A 1948 Cub should run at 1800 RPM at full speed.

Below is a pic of some of the governor linkage.
The high speed adjustment bolt usually needs to be set at about that position, or slightly up, if it is the original length bolt.
The speed should be checked with an automotive test tachometer, but if the Cub has a magneto, I guess you can't. The tachometer only works with a Battery Ignition unit.

[goxu1]

Did you buy it from TM ?

[Gary Dotson]

Adjusting the stop bolt will make no difference in the length of the carb. rod. It will only allow your hand lever to move further, applying more tension to the governor spring. I think that, sometimes, the lever, that the linkage connects to, may be tweaked a bit and the linkage needs tweaked as well. I've had to shorten them to get proper adjustment, before. Just make sure everything else is right, before doing this.

[fiddler]

I did get the rod from TM. It appears that it is the correct length. I will check the lever today for evidence of twisting. Possibly replace that part. I think I could pull that with the hood on the tractor later and buy a new rod to go with it after I shorten this one if I have to go there. There just are not a lot of possibilities here.... I am thinking the stop bolt may not be allowing the rod to get where it needs to for proper starting alignment. Who knows what has been done to this tractor in the last 71 years....

[fiddler]

OK so this morning I got back out there and did some looks. The speed change lever runs the full length of the throttle lever at the steering wheel. So from start to high speed the speed change lever moves, but the rockshaft (#13 on diagram IH15 from IH50 manual page 7 paragraphs 24-27) the rockshaft arm stops at about half way and goes no further. Is that normal? It appears that I have plenty of movement on the governor to go from idle to full throttle, but it is just in the wrong place. Wrong governor for this engine perhaps? They had an incorrect magneto on this when I got it, and the rear main bearing was installed backwards so the journal was covered which took out the main and one of the rods shortly after I got it. I had to rebuild the bottom of the engine and re-ring it. It runs real good except for these governor issues. I have recently retired and so now have time to look at it in earnest...

[Jim Becker]

The fit of the rockshaft extension (the shaft the rockshaft arm is on the end of) is often worn and loose. People have used several ways to tighten that up, including shims and JB weld. Is it possible yours is loose causing loss of movement? Could a previous owner have tightened up the fit but done so in the wrong position? Try removing it and seeing what the end looks like. You should be able to pull it out after unbolting the rockshaft bracket.

[Glen]

Hi,
The arm ahead of the carburetor that the rod connects to only moves to the rear until the throttle lever is about straight up and down, when the engine is off.

If you post some pics of what you have we could see if it looks right.

I sent you a PM, you get to them at the top of the page.

You can see what Jim means in my post above, in the first parts manual pic. Part number 8 can get worn in it's keyway, where the shaft number 30 fits into it. The key number 6 can get worn also.

With the engine Off, reach in from the left side of the Cub, hold number 8 solid, and turn shaft 30 both directions and see if it has play or wear. There should be no play or wear.
Use a good light if needed. If it has play or wear, it needs tightening. Looseness there can make the governor work slower than it should.
A new key can probably be found at a hardware store.

[fiddler]

I inspected that when I had it out. The shaft and woodruff key look perfectly serviceable. I went ahead and shortened the to the carburetor and went on with re-assembly. The governor now governs the speed of the engine. I am happy with the idle and the top speed. However, the tractor hunts or surges for the proper speed for about 10 seconds on a throttle change. I think that those adjustments are achievable after the hood is on the tractor. (hood now off to the side with long fuel line)... The new alternator is pegging the ammeter. I am thinking that will probably stop after I get a charge on the battery. It has not been charged for a long time. Maybe better to charge it with the charger first so as to not break the meter....? The governor has had the alignment pin ground off, for what reason?? Who knows..? Anyway I assembled it lined up as best as I could with the keyway. I saw a governor on ebay for 70 dollars and shipping. thinking it may well be worth it.... No wear on the slots where the magneto mates so maybe quite un-used... The arm on my governor goes WAY past vertical. Maybe 30 degrees past vertical. I am thinking a governor replacement is best. Is there a re-builder out there?

[Glen]

The throttle lever is supposed to use most of the notches on the quadrant from rear to front.
There are usually 1 or 2 notches at each end of the quadrant that are not used, the lever won't move into them.
I didn't mean that the lever is only supposed to go straight up and down.

The governor linkage has to be adjusted right, so the governor will work right.

The governor speeding up and down over and over can be caused by the yoke on the rod ahead of the carburetor being in the wrong position.
There can be nothing wrong with the governor, and it won't work right, because the yoke is in the wrong position on the rod.