Governor Gear - Mag 20

[mpatterson]

Anyone happen to have a picture of what the gear should look like looking down the fill tube hole? Mine looks to have a pin jammed in between it and the housing??

 

[mpatterson]

I just don't want to tear this thing down for nothing. Cub dealership I took it to said that was the problem. I didn't want to pay them to tear it down, couldn't afford it. Tractor was running away, could barely get it out of idle setting without it revving up so high and shaking the crap outta the tractor.

 

[mgonitzke]

That's the retaining pin. Looks normal to me, but can't see if the flyweights somehow came off without shattering the gear. Have you tried resetting the governor per the service manual?

 

[mjame]

I’ve got a good used one that I’m selling.
PM me if you are interested

 

[mgonitzke]

I would not recommend anything other than a NEW governor gear if you are going to tear the engine down that far. Used one is a time bomb.

 

[rfunk]

Just a thought, do you know anyone who has a "remote inspection camera" (borescope)? There are cheap ones, middle-priced ones, and EXPENSIVE ones available. You probably DON'T need even a middle-priced unit to get your eyeballs into where you can confirm exactly what happened. Yeah, probably will have to tear it down, but there is a chance (small, my guess) you get lucky, and can remove the pin from where it is jamming things, without opening it up. It would, however, leave you with a governor-less tractor. Rig a temporary "gas pedal" until you can afford to open it up. Much less than ideal, but limited functionality. YOU are then the overspeed governor AND the load governor. I get it, when you are working with limited funds, "make do" may be the target, rather than "make new" BTDT

 

[mpatterson]

That's the retaining pin. Looks normal to me, but can't see if the flyweights somehow came off without shattering the gear. Have you tried resetting the governor per the service manual?

Yeah, I did a bit more looking at it, you're right about the pin Matt. I didn't try resetting it per manual because the dealer told me the gear was gone.
Soooooo... I have it sitting on the bench now together.
How do those little "dogs" work? Right now if I turn the engine over by hand, they will "flop" when they reach the bottom of the stroke. Are they supposed to be spring loaded? I'm wondering if something else has let go and not the gear. I've rotated it around and the gear looks fine. A few of the teeth have a white colour in the plastic instead of that red/brown plastic colour. Not sure if they are stressed because something hit them or not? They are not chipped. The gear the it meshes with is all there, no chips. Can see the cam shaft move the exhaust valve fine too.
You mention weights Matt, are those the "dogs" that I'm talking about or is there more stuff attached to that governor shaft that I'm not seeing from that hole?

No on the camera.... I don't know anyone with those fancy tools! lol

Wondering if I should be trying to reset the governor like you questioned Matt before breaking down the engine for nothing. Can this be done on the bench or does it all have to go back into the tractor?

 

[mpatterson]

I’ve got a good used one that I’m selling.
PM me if you are interested

Thank you, but will skip the used stuff. I'm getting to the point of NOT putting used things on anything anymore. Starting to get frustrated with trying to save money and costs me money in the long run. Appreciate the offer though!

 

[mgonitzke]

Sounds like the governor gear is intact and functional to me. I don't think I'd take anything to that dealership again. They don't have a clue what they are doing.

You can reset the arm with the engine in the tractor. The procedure is in the engine service manual. I would do that before you tear it down. I don't think you are going to find anything wrong inside. The only other thing I can think of is that the little arm that is on the end of the governor shaft that is moved by the pin that comes out of the center of the governor when the flyweights are out has broken off. As long as the governor shaft doesn't spin around and around, everything inside seems intact and the external arm must have slipped on the governor shaft.

 

[mpatterson]

Sounds like the governor gear is intact and functional to me. I don't think I'd take anything to that dealership again. They don't have a clue what they are doing.

You can reset the arm with the engine in the tractor. The procedure is in the engine service manual. I would do that before you tear it down. I don't think you are going to find anything wrong inside. The only other thing I can think of is that the little arm that is on the end of the governor shaft that is moved by the pin that comes out of the center of the governor when the flyweights are out has broken off. As long as the governor shaft doesn't spin around and around, everything inside seems intact and the external arm must have slipped on the governor shaft.

Ok... So to set up the arm for the governor... in section 6A of the manual it talks about Early Tab version and Later Remote Mounted versions. How do I know which I have? The pictures are black and white photocopies - so can't see real well what they are trying to show. Also what would have caused it to slip on the governor shaft? Everything seems to be tight?

 

[sblunier]

Can you see both fly weights (little steel dogs) on the back side of the governor gear?

Do they flop around on their pins as you slowly roll over the engine?

If so, then the governor gear is probably OK.

You have a "tab" style fine adjustment (it is the little ear in your pic on the throttle cable linkage arm...it isn;t really critical for this adjustment though.

The arm may have slipped on the shaft. Do the governor adjustment as listed in the manual. Make sure the arm is loose on the shaft, they twist shaft as indicated and reset arm by tightening nut. This is the base setting.

Make sure the coil spring on the right side of the carb is connected to both the throttle linkage and the governor arm as shown (this applies the balancing spring tension to the governor.

Start engine and watch the governor linkage. If working correctly, it should move the carb linkage to try and close the butterfly at high rpm no load (this is what keeps it from overspeeding). Hopefully this fixes it.

If the governor arm does not move...it's a bad sign. The little pin that the weights push on has probably fallen out and is laying in the pan...so it doesn't control. Tear down time.

BUT, they really aren't bad to tear down, AND, you don't even have to pull the pistons if you are careful. I have taken several down before...pretty straight forward.

 

[mpatterson]

Can you see both fly weights (little steel dogs) on the back side of the governor gear?

Do they flop around on their pins as you slowly roll over the engine?

If so, then the governor gear is probably OK.

You have a "tab" style fine adjustment (it is the little ear in your pic on the throttle cable linkage arm...it isn;t really critical for this adjustment though.

The arm may have slipped on the shaft. Do the governor adjustment as listed in the manual. Make sure the arm is loose on the shaft, they twist shaft as indicated and reset arm by tightening nut. This is the base setting.

Make sure the coil spring on the right side of the carb is connected to both the throttle linkage and the governor arm as shown (this applies the balancing spring tension to the governor.

Start engine and watch the governor linkage. If working correctly, it should move the carb linkage to try and close the butterfly at high rpm no load (this is what keeps it from overspeeding). Hopefully this fixes it.

If the governor arm does not move...it's a bad sign. The little pin that the weights push on has probably fallen out and is laying in the pan...so it doesn't control. Tear down time.

BUT, they really aren't bad to tear down, AND, you don't even have to pull the pistons if you are careful. I have taken several down before...pretty straight forward.

View attachment 137240View attachment 137241View attachment 137242

I can see both dogs when engine is rotated slowly and they will flip down as they come around to bottom stroke. If I slide a pick I to the oil fill tube hole and move the governor gear front to back of the engine, it has maybe 1/16" play at most. All the teeth on governor gear are there. When I move the arm that is attached to the intake manifold it will move freely back and forth to stops. It does not spin around ask Matt said to check.

 

[mpatterson]

Well.... It worked! So Far anyways!
I did not tear down the engine as was suggested. I finished cleaning it up externally - years of grime and who knows WHAT! Frig'n mess to say the least. I put it back into the frame and cleaned out the fuel tank. Noticed it had a bit more crap floating around in it than I wanted going into a freshly bathed carb. It took a bit of cranking to get it to fire up, but it did. Let it warm up for almost 1/2 hour and all was good. Fired it up again the next day and let it warm up again and then spent the time setting the idle speed and top end speed. SO far - other than a pesky fuel leak that occurs over night - I have it solved engine wise. Last two days I have tackled the fuel leak. Tightening things up and making sure where it was coming from. End result, I needed to replace the o-ring on the carb bowl. It wasn't sealing correctly. So in a last ditch effort, I put the old one back on yesterday. So far today, engine is bone dry of gas. Woo hoo!
Now just need to order new gaskets for the intake manifold and the exhaust - there was only two between the four locations when I took it apart. So I have opted to put them on the exhaust thinking it would be needed there before the intake. Have you seen the price of those darn gaskets! That's just nuts.
I tell you... it certainly is nice to drive that tractor once again!
Thanks for all the help guys. I'll have to share some pictures once I get them downloaded.

 

[mpatterson]

Just a question....
What do you guys normally run for oil in the Mag 20 for summer use? 15W 40 or should I be using the low ash oil I have for my 100 I get from the IH Dealership? Just thinking from stand point of older motor and gets warm in summer when running mower on it.

 

[mfrade]

Oh Boy.. here comes the oil debate again. My preference is Mobil 1, 10/30, The book says to use SAE 30 unless it's the dead of winter. I just use the Mobil 1 year round. There was just another thread asking this same question. A lot of good conversation there.

 

[mpatterson]

Ok, will look that one up. It was the weight more than anything I was confirming what guys were using. So that's perfect for an answer. I agree, don't want to get into the big OIL debate at all

 

[mfrade]

I was thinking of this thread, give it a read.

https://www.ihcubcadet.com/threads/engine-oil-and-spark-plug-type.7569/#post-213744