Small Engine Repair: How to Adjust the Mechanical Governor on a Kohler V-Twin Engine



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**Always follow the instructions in your repair manual when doing repair or maintenance work on Outdoor Power Equipment. Manuals can be found at the manufacturers website.**

The 25HP V-twin Kohler engine fitted with a carburetor uses a centrifugal flyweight mechanical governor. The governor is designed to hold the engine speed constant under different loads. The bulk of the governor is contained inside the engine crankcase and is gear driven by the engines camshaft.

This is how the governor works. The flyweights on the governor move outward by centrifugal force as the engine speed increases. The higher the engine speed, the higher the centrifugal force acting on the flyweights. As the flyweights move outward, they turn a shaft called the cross shaft, which is connected to the governor arm. The governor arm is located outside the engine and is connected to the governor spring and the throttle valve on the carburetor. The governor spring force always tries to hold the governor arm and throttle wide open. When the engine reaches a speed where the centrifugal force on the flyweights and turning force on the cross shaft is equal to the governor spring force, than the engine will stabilize at that engine speed. The governed speed of the engine is always the point when the centrifugal force on the flyweights and turning force on the cross shaft is equal to the governor spring force. When the engine encounters a load, the engine slows down, and less centrifugal force is acting on the governor flyweights and thus less force is opposing the spring force. The spring is always trying to force the throttle open, so as the engine slows down and creates less centrifugal force on the flyweights, the governor spring forces the throttle open. This permits more fuel to enter the engine and increase the engine RPM. As the engine RPM increases, the centrifugal force on the governor flyweights increases until the force created by the flyweights acting on the governor arm is equal to the governor spring force. This back and force continues until a balance is reached and the engine stabilizes at a constant RPM.

Adjusting the governor arm and cross shaft is a simple job. You simply loosen the nut that holds the governor arm to the cross shaft. As the nut is loosened, hold the governor arm as far toward the carburetor as possible, and turn the cross shaft counter clockwise until it stops. When both the cross shaft and governor arm arm in this position, tighten the nut that holds the governor arm to the cross shaft. That is all there is to it. Kohler drilled a hole in the end of the cross shaft to make it easier to turn the cross shaft. Kohler recommends using a nail, but I found it easier to use a 90 degree pick.

Tools Used:
– 90 degree pick
– 8 and 10 mm socket
– Universal Joint
– Ratchet and Extension

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32 thoughts on “Small Engine Repair: How to Adjust the Mechanical Governor on a Kohler V-Twin Engine

  1. Hi I have the same engine and mower as shown here. I am having to run my mower at full choke or it will shut off. I take it the main jet is clogged? Can you take the bowl off of this carb?

  2. Thank you for posting this. I don't have the same engine as this and my governor is set up a little differently but because you explained how it is supposed to work so well I was able to fix mine. Thanks again. :o)

  3. i have a problem with my kawasaki engine 25 hp, i hope you can check my chanel, i up load a video of the engine, its online one video that i have so you will have no problem to find it, i already have a comment about what could be the problem but i would like to have your opinion too.
    thank you!!

  4. Great video. I recently rebuilt my kohler engine and was thinking that the governor needed to be at a specific spot so I checked your video out. Works perfect and am subscribing to your feed. Thanks again you saved me time because I don't have to figure it you with trial and error. Thanks again!

  5. Nice video. I know this is not a question/answer forum, but I thought you might be able to answer this. On my mower (18HP kohler), it boggs down really easily when mowing. I have adjusted the governor like you say. If I watch the governor and engage the blade, the governor never moves the throttle. I can reach in and manually move the governor and the engine will speed up. It is like the governor is not even working. Is it common for the internals of the governor to break? Thanks

  6. I have the kohler pro 20hp engine i got a strange problem. As i had a broken ignition coil (waiting for it as we speak) yours seems different a bit. That being said, i can open the throttle and it opens, however when i pull the lever down ….it seems to be stuck somehow will not go down. Until i push that arm down myself…might be dirt but not sure…what you think?!

  7. I have the 22hp kohler motor, but i don't have that linkage coming from the left side in the video.  Is that your chock cable?  I'm also wondering what is supposed to pull the throttle closed, because mine doesn't seem to close all the way when you pull the lever all the way down.

  8. I am having to fabricate sprints for a 22" deck walk behind mower. The springs are connected I don't know how it ran for a quarter of the front lawn… Your video gave me the exact understanding as to how my set up needed to be built. Thank You. Are you married? If so, lucky woman be grateful every day…

  9. I dont have a sears, I have an old case 448 – but this was helpful for me to understand basic governor operation. Thanks!

  10. Thanks for the video. I have a Kohler cv20s and when you go to higher RPM the the governor arm rapidly opens and closes the throttle. Is this a governor adjustment ?

  11. Thank you so much for this video i have a Kohler riding mower with the same engine, it's been hard to figure out but this will help tremendously.

  12. Hope you can help…..recently had to do some electrical work….burned wiring on the ignition moule (where the key goes) replaced that..washed the mower water and detergent. Also cleaned the carb with carb cleaner. Now…busts right off, but if I engage mower at low rprm as usual, it dies….bur if i REV it up it will mow….I know it is a carb problem…any suggestion…..I hate to takeit to a shop if it is something really simple to fix my self. PS this is a Kohler Courage 25 hp on a Gravely 50" curt

  13. excellent video. You are a gifted presenter: very clear, concise and to the point. This is the best description I've seen on how a governor works. I have viewed well over 500 hundred how to videos related to small engine repair and this is the best I've seen on this subject. My enthusiasm has caused me to use too many words which is ironic because the thing I admired most about your video is how each word means so much and there are no fill in wasted words.

  14. I had to replace the breather gasket which is behind the carburetor. When I put everything back together the engine idle took off screaming and I had no idea why. Your video was exactly what I needed. Thanks.

  15. Ive got a 98 Cub Cadet with a Kohler Command OHV 12.5HP motor, and I'd like to get it to go faster. would adjusting the governor let you get more RPMs out of it? That's what I've heard but I wanna make sure, and how to do it.

  16. having gov linkage problems, 23 hp kohler command, with a new gov return sprint ( due broken old one) one end goes in adj holes OK where does the other end attach?

  17. great info, just had one of those engines come in and I haven't had the chance to do that, thank you for posting

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