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I got the head back yesterday and got it all back together today. It all started fine and idled good for a few minutes but when I increased the rpm's it all of the sudden went wide open throttle and I couldn't get it slow down. I had to choke it to slow it down. I checked the governor linkage and I have it set correctly. The carb throttle keeps opening up if I don't hold the linkage. If I take the small spring off the throttle link and lever it will idle normally but will surge if I increase the rpms. I've tried different holes on the governor lever and it goes WOT every time if I keep the spring attached to the throttle link and lever. For whatever reason the spring keeps it from closing. I'm thinking something might have happened to the governor.

I was reading around the site and came across a thread where some mentioned a clock spring on the carb on a different engine. This could solve my throttle problem but I didn't see any clock spring on my carb. I need to try to find one that would fit. I'm sure one would have enough tension to keep the throttle from opening up on its own.
In the meantime my grass keeps growing.

The governor is not working.
Throttle opens up
Governor closes down
Most likely bob weights dropped off when you put it back together

What are the bob weights you mention? I put everything back I took off and there were no left over parts.

I would start by readjusting the governor other then that you have something hooked up wrong. I have no idea or ever heard of a clock spring?? Just what model command do you have? Also never heard of bob weights? unless berts is talking about the internal governor weights and just changing the head doesn't effect them?? as far as any Kohler heads I have ever changed..

I have a CV25 in a 1997 Craftsman 50" mower. I have the Kohler manual for it. I tried adjusting the governor every possible way. The problem I seem to have is the throttle wants to stay open. I can close it and it operates freely. The governor shaft turns about an 1/8th of turn or so. I can't imagine what could have happened to it while I was R&R the head an related components. It seems as the governor isn't doing anything as the rpms are going higher I could ever imagine this engine could produce. Once it revs nothing brings the revs down other than choking it and shutting it off.

When the engine isn't running and the throttle is wide open the carburetor throttle plate will be wide open. Then when you start the engine the governor brings it down to operating speeds. You should have two adjustments wide open throttle 3600 RPM's and idle speed 1200 RPM's. You will need a portable tack to make these adjustments. If you made all the right external adjustments and the governor still doesn't work then I would think it is a internal problem. You tube will show you how a governor works if you need help with that.

I don't think the governor is doing anything on start up. I'll have to see how the governor is supposed to function on the videos. If it is internal then I doubt I will bother fixing it. I've thought out a few ways to run the the throttle bypassing the governor. I think I can run it without destroying the engine because I've often adjusting engine speed when mowing. Some areas need more speed, some less. That's worked well for me.

1. Make sure throttle linkage is connected to governor arm and throttle lever on carburetor. 2. Loosen nut holding governor lever to cross shaft. 3. Move governor lever toward carburetor as far as it will go (wide open throttle) and hold in this position. 4. Insert a long thin rod or tool into hole on cross shaft and rotate shaft clockwise (viewed from end) as far as it will turn, then torque nut to 6.8 N·m (60 in. lb.)

Do this as per service manual? After doing this if the governor doesn't work you have a internal problem.

Yep I did that. I had it set that way before I started it. I'm not sure I want to tear into it. If it's s simple as pulling the engine and unbolting the lower case to get at the governor, maybe. I looked at the book and it doesn't illustrate the governor more than showing the gear in the pan and the cross shaft. I didn't get a good impression how it goes together by the book.

A couple of videos,
Both are Briggs, but Kohlers work exactly the same. I don't have URLs for Kohlers on hand

https://www.youtube.com/watch?v=50WipK9L8hc
https://www.youtube.com/watch?v=XbFyGRixoGA

Your governor might have been part of the problem in the first place they do stuff up from time to time

Thanks for the links. I was trying to find one that gave me a better idea.

I have a real good idea now about how the governor works on my engine. There should be some spring-like resistance when moving the governor lever which mine doesn't. It looks like the gear is plastic which probably broke. I wonder what genius came up with using plastic parts inside an engine?
I looks like I 'll be pulling the engine again. I've done it twice before and it wasn't too difficult. The governor gear sits in the oil pan on the CV25. Might nor be too hard to repair.

Things always go quicker the second or third time around.

Plastic gears have been in engines for a long time. That doesn't mean they're better than metal gears; they're not. I had a 1969 GTO that had a fiberglass cam sprocket. It failed.

Yes, I've known that plastic/non metal parts have been used in automotive engines for quite some time. I was a little surprised to find something like that in this engine. It must be a common part to fail. I was looking on ebay for them and one seller had already sold over 90 from his listing.
Something like this is a ticking time bomb. It's only a matter of time before it can fail. When it does, the engine can destroy itself if a user doesn't shut the engine off in time.

The part I don't understand is why did the governor gear destroy itself replacing a head. The head and governor aren't connected in any way. Did you remove the intake manifold and in doing so bend, disconnect, and not put together the governor linkage the right way?? Just maybe Mr. Bob Weight did have his hands into this repair.

I had to pull both the intake and exhaust manifolds. I had to remove the lever off the governor shaft as there were baffles that had to be removed to get the head off. There's a lot of stuff in the way before the heads can come off. I put the lever back on the way it shows in the book and I double checked everything before I started it. How the governor went FUBAR is beyond me.

This is getting more confusing as we go.. Isn't there a clip that holds the linkage to the lever? :confused2:

This is how the lever is attached. There are clips and a spring. I needed to remove it to get to remove the baffle on head #1.

Kohlers commands have stuff bolted to the bottom of the heads that has to be removed, the intake has to be removed, the throttle and choke cables, are attached to the top of the blower housing with a heavy duty air cleaner on some units only with the blower housing that all has to be removed on them to get the heads off. I don't remember taking the governor arm off the rod though.

Taking the lever off shouldn't have ruined anything so it's probably only a coincidence that the governor broke. I bypassed the governor for now and the only thing different is throttle is more sensitive and mowing takes frequent speed adjustments. I mowed for about an hour this evening and it ran mowed fine. There was a little relearning involved to get that happy medium. Once the grass goes dormant from the lack of rain and higher temos, which should be soon, I'll fix the governor.

The governor gear has little tabs in the center of it that helps hold it in place when assembling the case. Kohler always recommended replacing the gear if it was ever removed from the little shaft that the governor gear rides on because the little tabs can be damaged when removing the gear from the shaft.(Its best to never remove the gear from the shaft unless absolutely necessary). If the tabs are damaged, it can allow the gear to become dislodged upon start up. It's always best to replace both the governor gear and the governor gear shaft together if there is ever a governor gear failure because the little groove in the governor gear shaft can be worn which could cause damage to the governor gear itself. Before removing the governor gear shaft from the case. measure the height of the shaft from where it protrudes from the case and install the new shaft at the same height making sure the little groove in the governor gear shaft is at the same height also. I always replaced the button that goes in the center of the governor gear also and I always put a little JB weld on the gear shaft where it fits in the hole in the case. Like has been stated, if there is no resistance on the governor arm when the engine is running, the gear isn't doing anything and is probably dislodged? I do it this way because I have learned it the hard way.

Those are some great pointers for when I get around to replacing the gear. I've got about 2 more hours of mowing that really needs to get done. After that I'll pull the engine and drop the pan to see what happened in there.

Well the mystery of the WOT wasn't solved by pulling the pan. I opened it up Saturday and the governor gear looked OK. The weights rise when I spin the gear with no binding of the plunger as I would think it should. The shaft that goes to the lever was undamaged. It should have worked when I had it adjusted. I ordered some new springs for the lever and the one that goes on the throttle shaft itself and I'm hoping that will fix it. Without the governor working, it's a bit of a pain to vary the engine speed just right while mowing.

I got it all back together with new springs today and it runs great. It idles fine and I can adjust the engine speed with no more issues. It looks like it just needed a new spring.
Now i have a new problem. The POS won't move and the belts are the way they should be. Time for another new thread.

The running great was short lived. After I took care of the transaxle issue I raised the engine speed a little and the rpms went super high with no control again. I hooked up a counter spring so I could at least mow again.
I got most of the mowing done but the battery crapped out. It just quit on me. No click no nothing. There was an odd smell and I noticed the battery sounded like it was boiling. What else will go wrong next?

"Super high rpm" probably fried something in the voltage regulation circuit. Your battery probably got cooked from receiving full alternator voltage.

I immediately shut it off when the rpms went out of control again. I was able to control the rpms after I added a counter spring to the governor lever. I was moving at moderate speed when the battery fried. The battery was 9 years old so maybe it shorted out or something. If not then did something in the charging circuit go crazy?

You'll know when you fire it up again. Check the voltage at the battery then check again with it running. If it's much over 14-15 volts, you'll cook another battery if you run it very long.

That's all I need is another problem. I can't figure how an overcharging issue can develop. I had a motorcycle many years ago that had the same issue but I never investigated it since I always used the kickstarter and didn't rely on its lights.

Since you mention motorcycles, it was common for old Triumph Thunderbird or Bonneville motorcycles to blow the headlight if you over revved it.

Voltage spikes are not good for electrical components and one time can do it.

I hope it didn't fry my ignition coils. I replaced them last winter. I've lately gotten tired of throwing money at this thing although it hasn't been much over a $100 yet. It's still less than a new mower.

I doubt that it did...otherwise, it wouldn't have been running for you to shut off.

More likely something in the charging circuit.

Who knows? Maybe your diagnosis of the 9 year old battery giving out is correct.

I'm hoping that it's just the battery. It's just odd to see a battery seemingly boil like it did. I wasn't paying attention to the gauge before this happened. It was cranking perfectly until about half an hour before this. I had shut down the mower and then when I wanted to start again, the battery seemed like it was low on charge. I hooked up a charger and after a short charge was able to restart easily. It ran ok for a while and then it happened.