Farmall M high idle

I?ve searched and read over other people having problems
with their M idling high and won?t go lower and I am stumped.
First off I kept having trouble getting the thing started it would
hit every so often and finally figured out that after 4 months
the gas went stale. Filled it full of fresh gas and it fired right up
but at a high idle. The throttle lever is all the way low and it
sounds as if the lever is all the way back. Let me also include
that this is on a brand new engine rebuild. New pistons
sleeves, crank turned, new lifters, new valves, head reworked,
450 camshaft the whole 9 yards. I also rebuilt the Governor
with new bushings, new needle bearings, new thrust bearing
and washer and also a new front bearing. I adjusted the
Governor per the manual and as was suggested by setting
?close? to what I thought the low idle on the carb should be
then adjusting the lever on the threaded rod so the pin slides
in freely at max throttle and it also slides freely at low throttle. I
have the Governor low idle stop bolt set and even backed it
up a few turns more and still no lower idle. The max is set just
against the stop in correlation to the max throttle position. I
have double checked my governor throttle tube to carb
connection and the little tang from the Governor is inside the
middle of the fork on the carb connection for the throttle plate.
I even pulled off the bowl and verified the opening and closing
of the throttle plate. The Governor spring is also loose when
the throttle is all the way down with no tension on it. I have
checked my timing thinking it may be timed to be ?putting a
load? on the engine. I turned the engine to TDC on the
compression stroke for #1 cylinder and then opened up
distributor and tuned it so the points just began to open with a
timing light and locked it down there. The pointer is pointing
toward #1 spark plug and is cranking up fine now. I noticed
that when I cranked the engine gas was coming out the
bottom of the carb when it was not firing. It does not however
leak just when sitting and fuel turned on. I tried adjusting the
carb I got the idle screw turned all the way out and played with
the high idle some but would a carb problem cause the issue
I?m having cause I?m scratching my head. Sorry to ramble on I
just want to describe this as clearly as possible. Any tips tricks
or all suggestions wanted it just seems really odd.
 
If you have the tang that goes in between the ears on the governor throttle shaft inside that tube from the carb to the governor it will not idle down with the throttle lever. Or will not throttle up with the lever. Depending on which side of the deal you happen to get it on.
 
D Slater had a reply its still on page 6. That i wish i had seen couple yrs ago, about gov lever to throttle- bell crank that helped me get idle down
 
This pictures will clarify hopefully on what I am referring to this isn?t my tractor just an example but so I have the tang in the first picture installed where the arrow is pointing in the second picture
cvphoto11911.jpg


cvphoto11912.jpg
 
Yes that post was very helpful on setting up my linkage correctly I?m just confused as to how it?s idling up that high with throttle in low position it will idle up even higher and go back down to a ?lower? idle but it?s still way to high
 
loosen 2 screws on throttle tube front connection by govenor tower lift up on throttle tube, tube should move up, while holding pressure up tighten screws idle speed should return
 
It sounds as though you are sure you have the tang in the right place. Is it possible to install carb with either the governor tube pushed to the side, or else unhook it inside the governor? What I am saying is try to run throttle at carb manually by hand. That's the only way to know for sure if it's the carb or governor.
 
I rebuilt my throttle shaft with a kit that come with bushings, new throttle shaft and lever but I know I did install the lever on the right side. The lever I am referring to is the one that connects to the Governor shaft where the pin slides through the lever and Governor connection where the breather tube is. I?ll give that a try tommorow I hope it helps lower it some.
 
I?m not sure exactly what you mean as far as running it by hand because wouldn?t I have to remove the throttle shaft to do that or you mean unhook the carb to Governor pin and just rotate that lever up and down?
 
your not rambling on! your just stating what u have done and as more people should be giving info like this . im quite sure you have the tab in the centre of the slot where it should be. everyone seams to think u don't. timing wont do that. plus it normal for gas to leak when choking engine. I am thinking you have something in the governor not right or its an adjustment. hard to tell without eyes on the subject.
 
Is the throttle linkage free by the rocker arm cover? I was having problems with an M and found the pivot was binding up and not allowing the throttle to work like it should. The springs allowed the throttle to move enough to seem like it was right but wasn't.
 
Here?s a picture of the Governor after I got done rebuilding it not the most helpful photo but the spring is loose when the throttle lever is in its lowest spot and the carburetor butterfly is closed almost completely. Seen this with bowl off and linkage all hooked up like normal
cvphoto11925.jpg
 
remove vent tube screws on top of governor tower, loosen vent ferrule nut rotate pipe up make sure away from fan start tractor and pull up on governor rod clevis engine should idle then proceed to adjust as I stated in previous post
 
When installing the carb., it is possible to have the venturi in the carb., upside down. I do not remember what problem this causes and I am not saying that you have done this. I'm just trying to be helpful.
 

Good picture of your governor, Trent. Looks like you have made bushings for the spring holes. (Good improvement). Now, I would back out the idle speed screw on the spring lever, so instead of the spring being loose at idle, there is a slight pressure against the rocker assembly. This will allow the throttle plate to close completely if the idle speed screw on the carb is backed out far enough. If this doesn't help the too fast idle problem, maybe check for an air leak between the carb and manifold as well as between the manifold and head. Let us know if you find anything.
 
If youre 100% sure the carb connection is right, it almost has to be a problem in the linkage. If you can get it to idle by moving the curved piece at the gov., then its in the linkage from the throttle to there. If not, its in your adjustments in the gov. Without seeing it, I wouldnt guess which one is off.
 
Well since i am not standing there with you and you say you have no control on the throttle they you may boy eith missed getting the tang in the slot or ya messed up when ya worked on the governor . You say you have gas running out of the bottom of the carb , well this is and UP DRAFT carb and they will do this when you stop cranking the engine or when you shut them down . As what goes up while in motion will fall down when motion stops . And LIQUID GASOLINE going up and yes there is a lot of liquid that goes up when the engine is being cranked and while running once you stop cranking or shut the engine down all that comes back down and drips out the wheep hole . Next are you sure you did not install the throttle plate wrong . SEEN THAT HAPPEN several times when people think that they can do DIY it to save fifty bucks then come looking for answers .
 
If my governor lever is not all the way up pushing against the thrust bearing towards the weights it would not idle low is this correct? I?m not near my tractor but I believe this may be my problem I thought I had everything set right I will double check when I get home
 

The hand lever needs to be able to move the speed control lever inside the governor housing each way, so that both adjustment screws will contact the housing.
 

Trent, after rereading all the responses on this thread, I believe it's likely the problem comes from your rebuild with the new governor to carb throttle shaft kit. I think the bronze lever is too far counter clockwise (when viewed from the front) in relation to the carb or (tang) end of the shaft. Do the new shafts come pre-drilled? Did you have to turn the clevis on the vertical linkage down when you did your adjusting? Just one more thing to check.
 
Thats kind of what i meant, the lever on the back of gov, set with throttle lever on steering post on low idle. I am NOT very experienced, but i believe i pulled that lever up, and matched the throttle lever at low, by adjusting at bell crank. So my issue was i couldnt push throttle lever low enough to get idle down. Maybe i am full of it lol! That fix my issue, my m was disassembled too. So i get your confusion.
 

Fred, what I was referring to is the horizontal throttle shaft assembly from the governor to the carb. My point is that the bronze lever may need to be turned a few degrees clockwise on the throttle shaft.
 
I guess what I?m asking is that the lever the arrow in pointing to in the picture is suppose to be up snug against the thrust bearing assembly. I may of not pulled up enough on my Governor linkage and got to much space between the weights and the thrust bearing which would makes sense as to why it?s running wide open
cvphoto11984.jpg
 

Trent, True, if you did not pull the linkage rod all the way up, in order to fit the pin through the clevis with the throttle plate wide open, you would of had to turn the clevis up on the linkage rod. That could result in the throttle plate not closing at idle, resulting in a fast idle.
 
This is what the governor looks like with throttle all the way down I pulled up on lever as I pushed down the Governor throttle lever and got the pin to slide freely the first two pictures are of the throttle at idle the second two pictures are of the throttle wide open. What?s even stranger is the fact that I had the throttle butterfly on the carb closed by pushing the throttle lever at steering down I verified this by unbolting carb and looking down into the top and the engine is still reved up
cvphoto11986.jpg


cvphoto11987.jpg


cvphoto11988.jpg


cvphoto11989.jpg
 
I will let you know I?ve told a good friend of mine what is going on and he is convinced it?s a carb problem. I?m not gonna doubt him at this point it just seems odd a carb would cause this much over rev. I did notice that when choked the engine idled slower
 


Trent, from your last set of pictures, it looks like you can back the idle speed bolt out about 3 turns. I know you said the throttle plate was closed when you dropped the carb down but it won't take much to try backing it out. Another simple check would be to : With the throttle hand lever way forward, remove the clevis pin and see if there's any more movement downward of the throttle shaft. Do you remember if you could read the number 12 degrees on the top back side of the throttle plate when in the closed position? What Tractor vet was talking about.
 
With carburetor flange level and throttle shaft to wide open stop pin, looking from front of throttle tube the little brass lever should be awful close to the 11 o clock position if tang is in carburetor shaft notch. Doesn't need to be exact if in adjustment range of vertical rod and nothing binds or contacts housings.
 
I think the issue is governor related. I rebuilt my engine on my M along with the carb and it did a similar thing. Ran and high rpms and would not throttle down. Had to adjust the governor. At some point in it's many years someone else must have adjusted the governor to compensate for the wear on all the old parts.
 
Yes it is very close to the 11 o clock position and nothin is binding. It was idling low before I rebuilt the carb and Governor and now it won?t and I put the Governor back exactly as I thought it was and not sure if somehow I got the carb out of wack as my buddy thinks it?s carb related
 
Yes I did verify that I removed the pin and turned the brass throttle lever going to carb all the way up to fully open the butterfly and all the way closed and my pin slid in freely at both places. I did not happen to check to look for the 12 degree number but when I have it off again I will. My next step is to get up with a guy I know and see if he will let me swap carbs to see how his runs with my carb to narrow down my problem
 

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