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Discussion Starter #1
Hi,

I just purchased a 1976 Jim Dandy tractor serial number 40322. There was black smoke when the tractor started and the seller said the carburetor needed adjusted. The engine speed was also revving up and down somewhat and the throttle would not stay in the fully open position because of the spring tension.

I bought a tachometer to adjust the carburetor speed, sprayed the linkages with WD-40, and adjusted the throttle cable so that the throttle would open all the way.

I tried to adjust the governor but the shaft continues to turn and does not stop. I understand the only way to fix this is to disassemble the engine. My understanding of the governor is that it controls the engine speed by adjusting the throttle on the carburetor. When I try to adjust the carburetor, the engine speed varies from about 2200 rpm to 4000 rpm when I hold the throttle at the slowest setting where it does not stall.

Am I wrong in thinking that the engine should run smoothly at one speed when the throttle is held in a fixed position? I think that the carburetor needs to be rebuilt and that after rebuilding the carburetor, I could run the tractor temporarily by hooking the throttle cable directly to the carburetor. I understand that that is not an ideal fix, but I just got the tractor and want to play with it without rebuilding the engine.

Would bypassing the governor cause any damage to the engine? How is the upper limit engine speed set - is that controlled by the carburetor or the governor?

Doug
 

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Would bypassing the governor cause any damage to the engine? How is the upper limit engine speed set - is that controlled by the carburetor or the governor?

Doug
Technically, no. you just wont have any way to consistently control top speed of the engine. upper limit engine speed is controlled by the governor.
You could adjust no load speed to something close to upper limit engine speed but your probably gonna lose a decent amount of rpm's when your under load, not to mention it might be a scary balancing game with your throttle cable since a millimeter difference in cable extension might be the difference between underspeeding or overspeeding the engine.
 

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Look at the simple things first. Is there any way the lever on the governer has been loosened on the shaft? By "kept turning" I don't know how far you actually went.

It does sound as though the engine is running rich with all the black smoke. Check the throttle shaft on the carb. If it's loose and can wiggle around in there, then the carb is sucking air which will make the engine run erractically.

You are right, the engine should run smoothly if the throttle is held in one spot. The only time it would change is under load when the governer kicks in.

I re-read your post and it does sound like the engine needs to come apart to repair the governer. I am no expert on this as I have never done one.
 

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To test the governor, loosen the clamp on the governor arm. With a small screwdriver, turn the governor shaft to the left until it stops. Then, start the engine and manually control the throttle- you should feel the governor try to twist the screwdriver. If not, or if the governor shaft does not reach a stop point, the disassembly will be required.
 

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Look at the simple things first. Is there any way the lever on the governer has been loosened on the shaft? By "kept turning" I don't know how far you actually went.
Thats true, take it easy, don't do like this idiot that i know. the governor on my jd140's 321 stopped governing and instead of checking the small stuff i ***-umed that my governor gear blew up. i changed the governor gear just for s&g, but in the end the governor arm had only slipped on the shaft. nothing wrong internally. i turned a five minute fix into a substantial project.
 

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Discussion Starter #6
Thanks for the advice. I will rebuild the carburetor first and see how it works. I think I turned the governor shaft enough for it to have gone in a complete circle a couple of times. I hope that is not the problem.

Doug
 

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Hey Doug,

Just being curious, did you pick up your Jim Dandy in Griffin? I had looked at one for sale a couple weeks ago.

john
 

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Thanks for the advice. I will rebuild the carburetor first and see how it works. I think I turned the governor shaft enough for it to have gone in a complete circle a couple of times. I hope that is not the problem.

Doug
If you did indeed turn the shaft without hitting stops then you're in trouble, so to speak. I would guess you lost the shaft paddle, which is probably something that happens as the service manual mentions checking out the weld that attaches it to the governor shaft. i've never seen a grenaded governor gear, and my 30+ year old gear looked pretty good when i removed it. Do these gears really grenade?
 
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