Farmall cub engine "lopes"

CDrake

New User
Seems like I'm "fighting" the accelerator, doesn't seem to get to full throttle. What exactly is that "gooser" ? (my term- the long arm connected to the thottle of the carb), it has a mind of its own and opens the thottle,then retads, as it is connected back to the magneto. As I said, engine "lopes".

I an at a loss to figure out how this engine accelerates; does the magnito advance, and then control the gooser which pushes the thottle open to get more revs out of the engine?

If I put under load, seems to iron out, however, still not getting full power.
Could an air leak do this? Or maybe just a bad condenser-it used to happen while driving, and then just as quickly disappear.

Any reponse would be greatly appreciated.
 
Mag and carb are 2 different parts of the engine and do not effect each other. If your saying it surges from idle to high throttle then back down you have a clogged main jet on the carb or a bad govanor and weak spring. If you grab the rod that goes to the govanor from the carb and you can hold it steady what happens?? Also what happens if you choke it does that hurt of help?? You can also try this. Pull the main jet cap off since all the ones I have seen on this tractor had a non-adjustable main jet and let gas flow out of the cap for a few minutes. You might also poke small wire into it to make sure it is not clogged up
 
Now, I just rebuilt the carb....however, it did this loping before, somewhat. If I hold the governor (the gooser?) and push it forward, I can get a lot more revs out of it, however, I can still feel it trying to go back and forth under its own volition.Yes, a (very) little choke did seem to help.

Not sure what you mean about the main jet; wouldn't you have to remove the entire carb to get to this?
 
If that carb if like most cub carbs the main jet sits down low and forward on the carb. It has a brass plug sort of thing covering it. Remove that brass plug turn the gas on and you should get a steady flow of gas there. Since you said choking it help that tell me you missed something when you did that carb rebuild.
 

Lopeing or more commonly called "hunting" is usually a symptom of a problem with the governor or linkage. Many governed motors will do it on first start up, then smooth out after a little warm up. Since the linkage is usually much easier to get at than the governor, it would be good to start out by checking governor linkage connections and correcting any that you find loose.
 
Not gonna argue with you, but in my experience, the most common cause of governor "hunting" is carburetor problems. The idle circuit and the load circuit both need to be operating properly and be adjusted correctly (as well as any "transfer passage"/circuit in the carb) or the engine will falter as it it comes up to governed speed and the governor backs off the throttle, then the governor will jerk the throttle back open, causing "hunting", which sounds EXACTLY like the problem he is having. Of course, governor or linkage wear pr maladjustment certainly is a possibility.
 
Thanks to both who have responded. I drained the main jet; no change.
Have liberally applied PB blaster to the pivot on top of the governor; it moves much more freely, but still hunts, off and on ,while I am driving, pushing (has a plow), of just standing still.

As mentioned, I will keep putting the blaster on that pivot, as other far pivot is OK. Can't see where else you could free up binding. If this doesn't work after a few days, what is next step? Governor disassembly?

[b:31c3ae8555]Just read last post; got me to wondering about that carb; didn't really adjust anything during the rebuilt (basically just replaced gaskets and needle valve,etc.).[/b:31c3ae8555]

Wonder about the wisdom of attempting to resusitate a (50-60 YO) carb.
Futzed around with a Weber 2 barrel on one of my Alfas for the longest time; finally just paid $200 for a new one, put it on, and presto, has run like gangbusters ever since. So, maybe a new IH carb is indicated?

Thoughts? (And cheapest place to get one!-looks like they run more than that DGV 36/32 that I got fro Peirce Manifold!)
 
Bet you have some loose junk in the carb. Since the main jet sits low it can clog up easy form any small piece of dirt or rust. I would pull the carb drain plug out of the bottom and let fuel flow a couple minutes. Catch it so you can use it and also to look for dirt etc in it. Also did you use a small wire to poke out the little hole in the main jet?? If not then do so it can only help.
As for comparing a Weber carb on an Alfa to that car it would be like comparing a Model T to a Corvette.
Years ago I had a 1967 Alra Roemor which had 2-2 barrel side draft Webers on it and boy was that a fast car
 
(quoted from post at 14:58:03 01/13/13) Thanks to both who have responded. I drained the main jet; no change.
Have liberally applied PB blaster to the pivot on top of the governor; it moves much more freely, but still hunts, off and on ,while I am driving, pushing (has a plow), of just standing still.

As mentioned, I will keep putting the blaster on that pivot, as other far pivot is OK. Can't see where else you could free up binding. If this doesn't work after a few days, what is next step? Governor disassembly?

[b:352fff8f76]Just read last post; got me to wondering about that carb; didn't really adjust anything during the rebuilt (basically just replaced gaskets and needle valve,etc.).[/b:352fff8f76]

Wonder about the wisdom of attempting to resusitate a (50-60 YO) carb.
Futzed around with a Weber 2 barrel on one of my Alfas for the longest time; finally just paid $200 for a new one, put it on, and presto, has run like gangbusters ever since. So, maybe a new IH carb is indicated?

Thoughts? (And cheapest place to get one!-looks like they run more than that DGV 36/32 that I got fro Peirce Manifold!)

I have never encountered binding governor linkage, it has always been loose.
 
I've had the carb apart, and did take out the main jet, poked it with a wire, and put it back. No change.

Just mentioning that messing with really old carbs sometimes seems like a waste of time-a new one can work wonders!
 
I have been rebuilding carbs now for well over 3 decades and most old tractor carbs if done right can be rebuilt and work just fine. Now some of the car carbs that is another story also BTDT. With a tractor carb you have to be able to soak it for 24 or so hours then use a piece of wire or as I do a torch tip cleaner tool and poke out each and every passage way and blow air and spray carb cleaner in all the passage ways and even then maybe open it up a 2nd time. Have a friend who has a cub that surges when first started and has even since I rebuilt the carb but after a minute or 2 smooths right out so have not opened it up again and that was 10 years ago and it still runs the same way and he has used it for many hours
 
Have done as suggested; took carb apart, soaked in 1 gal bucket container of carb cleaner (from Advance Auto) for approx. 24 hours, then cleaned it with spray carb cleaner, blew it out with compressed air,reassembled all, and re-installed carb.

Intially, it seemed that this had improved things; I fiddled with the two adjustment screws. Then ,it started to hunt again, exactly as before.

BTW, I have also sprayed about half a can of PB Blaster on the near pivot to the governor (as well as the far pivot, near the throddle linkage).

Where should I go now?
 
(quoted from post at 09:45:46 01/19/13) Have done as suggested; took carb apart, soaked in 1 gal bucket container of carb cleaner (from Advance Auto) for approx. 24 hours, then cleaned it with spray carb cleaner, blew it out with compressed air,reassembled all, and re-installed carb.

Intially, it seemed that this had improved things; I fiddled with the two adjustment screws. Then ,it started to hunt again, exactly as before.

BTW, I have also sprayed about half a can of PB Blaster on the near pivot to the governor (as well as the far pivot, near the throddle linkage).

Where should I go now?

As I posted before, The common problem with governor linkage is not need of PB blaster, but the opposite. The holes and connections get overly loose and the spring can get slack. Your owner's manual should give you instructions on adjustment but here it is very basically: Disconnect the rod from the governor arm to the carb, open throttle butterfly fully, set the throttle to full, position the rod end next to the throttle arm of the carb. The rod from the governor to the carb should be in the exact position to slip together. If not, you need to adjust the length of the rod to where they will slip together.
 
Ok; disconnected the governor linkage from the throddle rod, pushed the rod all the way back (open), pushed the throddle lever all the way forward. It lined up; however, there was some slop, so pulled the linkage back and reset the adjustable fork so the two would line up.

Started it; still hunting. Boy, frustrating......Governor spring weak?
 
(quoted from post at 13:33:21 01/19/13) Ok; disconnected the governor linkage from the throddle rod, pushed the rod all the way back (open), pushed the throddle lever all the way forward. It lined up; however, there was some slop, so pulled the linkage back and reset the adjustable fork so the two would line up.

Started it; still hunting. Boy, frustrating......Governor spring weak?

You said "however, there was some slop," Therein could lie the problem, that I have been referring to all along. See if you can find a way to temporarily take up the "slop" and with the slop out of it see how it does. If that takes care of it perhaps you can drill out and put in a larger pin or whatever goes there, on your particular tractor. It is not uncommon for some engines to hunt a little when first started cold. most smooth out in a few seconds. Old Detroit Diesels would hunt for a minute or better when started cold.
 
I should clarify; the "slop" is in the axle itself, NOT from the linkage hook up (adjustable fork). The arm that the fork attaches to can be moved, forward or backwards in an arc about a quarter of an inch at the fork attachment point.

The arm was moved forward (in its position towards the front of the tractor) and lined up perfectly with the adjustment fork. When I adjusted it, I moved the arm back as far as it would go, and adjusted the fork to line up and put the clevis back in. This is how it is right now.

I am looking at an exploded view of the governor right now....Maybe a worn woodruff key,bearing,weak return spring,etc. results in the slop? Otherwise, I wouldn't have a clue how to remove that movement from the rockshaft assembly.

What about the governer speed change lever stop screw (on top of the governor casing)?
 
(quoted from post at 08:13:00 01/20/13) I should clarify; the "slop" is in the axle itself, NOT from the linkage hook up (adjustable fork). The arm that the fork attaches to can be moved, forward or backwards in an arc about a quarter of an inch at the fork attachment point.

The arm was moved forward (in its position towards the front of the tractor) and lined up perfectly with the adjustment fork. When I adjusted it, I moved the arm back as far as it would go, and adjusted the fork to line up and put the clevis back in. This is how it is right now.

I am looking at an exploded view of the governor right now....Maybe a worn woodruff key,bearing,weak return spring,etc. results in the slop? Otherwise, I wouldn't have a clue how to remove that movement from the rockshaft assembly.

What about the governer speed change lever stop screw (on top of the governor casing)?

I am not familiar with how the governor arm comes out of the housing on your tractor. I took a look at an Oliver today and it is pretty much the same as the Fords. You must have a worn out bushing which necessitates dis-assembly to replace.
 
Yes; like I said, maybe the slop in the linkage is the troublemaker. When I pull out laterally on the far linkage (near the throddle arm) sometimes the hunting stops.

Bearings and spring aren't that expensive. Think I've found what I need at TM Tractor. Any other good sources/places I can go for advice?
 
"Any other good sources/places I can go for advice"

farmall
cub
dot
com

good article on governor and how to fix your issue

GOOD LUCK

Ron
 
If you want help with a cub, go to the "farmall Cub" website. There are some great people over there who are knowledgeable and very helpful.
 

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