Role of the Governor????

[mattd860 162]

Can someone briefly explain what exactly a governor is supposed to do? I don't need to know HOW the various types of governors work. I just need to know what they're supposed to do.

Unless you want to elaborate more - all I need to know is if a governor is supposed to increase engine speed, decrease engine speed or both.

I

[wallfish 16,105]

supposed to do both of what I listed above

The throttle lever should apply tension, through a spring, to the governor arm in order to open the throttle plate on the carb. This will limit or Govern the throttle on the carb. The governor always applies tension to close the throttle plate. The higher the RPMs the more tension it will apply to close it.

[rmaynard 14,976]

Section 6 of the Kohler Service Manual for K-Series engines has a very good explanation of how the governor works. Boring, but interesting reading.

Bob

[mattd860 162]

Thanks for all the input. There still doesn't seem to be concrete info on this. I understand the governor is supposed to control the engine speed by "automatically" adjusting the carburetor (based on spring tension). However, even on the Kohler applications, the governor can never open the throttle plate farther than what is dictated by the throttle lever. So if you open the throttle 50% via the throttle lever, the governor cannot move the throttle past this 50% point. If you notice, the governor springs only operate in tension, not compression. In order for the governor to automatically rotate in both directions, the governor spring would have to be both a tension and compression spring. This is what's confusing the crap out of me. I just can't see how the governor on the Kohler or Tecumseh engines functions in order to maintain engine speed.

[Coadster32 793]

The spring pulls it one way, and the fly-weights on the internals of the motor throw them out the other way. The faster you go, the more the weights throw out, and the less spring tension you have.

Strange that you want something in concrete, but yet you're not interested in the techs of it. :thumbs:

[mattd860 162]

Well i was really just trying to avoid a long drawn out description of the different types of governors like the manuals and tech article love to do. I sort of understand that the governor spring is always supposed to be in tensions but on all of my motors (4 Kohlers & 1 Tecumseh) the spring is never under tension unless the governor arm moves to close the throttle beccause in order for the lever to open the throttle, the tension spring will have to compress which is not possible. whether the fly weights want to move the lever to open the throttle is a non issue since the lever is physically unable to swing in a way to open the throttle. It is only able to swing in a direction to close the throttle and when it does, only then is it in tension by the spring which is pulling it the governor lever back whatever point you have the throttle lever set to. I know there is something that I'm missing and frankly, I'm a bit frustrated at myself for not being able to see the obvious but hopfully you guys here can keeep helping me out.

[wallfish 16,105]

The internal fly weights connected to the governor are what gives the tension to close the throttle plate. The external spring connected to the throttle lever pulls tension in the opposite direction. Equal tension in both directions is how the desired RPM is achieved

If you go to your motors, you can easily move the governor back and forth when it's NOT running. Start the motor and try to move the governor arm with your finger and you will feel the tension. The higher the RPMs the more tension you will feel.

When the motor experiences a load, the RPMs will drop causing less tension from the internal fly weights. As this happens the spring tension from the throttle lever gains tension. This greater amount of tension from the spring causes the governor lever to pull open the throttle plate on the carb until the RPMs are restored to the original position and equal tension in both directions. This all happens very quickly so you may not even notice that this is happening unless you apply a heavy load to the engine.

I think what you are missing is the understanding of the internal fly weights that provide the tension to close the throttle plate. This is the best I can explain what I think I know. Maybe an expert will chime in with a better explanation that is more user friendly.

[Save Old Iron 1,564]

Matt

here is my quick(est) - non technical attempt

open throttle to say 3000 rpm - this is the fastest you wish the engine to run

engine starts - in this instant in time is underspeed to what yuour throttle setting dictated - carb throttle plate opens against no gov spring tension - engine revs up to 3000 then the governor - sometimes centrifugal, sometimes air vane driven, starts to pull against your mechanical setting - engine is prevented from going any higher in rpm because gov arm / springs starts to pull throttle plate closed - a little - until an equilibrium is formed between spring tension pulling carb closed and engine wanting to exceed the RPM dictated by your operator (throttle) setting.

now run the tractor into a load, its natural for the engine to bog a little (decrease RPMS)

when you decrease engine RPMs, you loose some of either the centrifugal force on the governor or airflow on the air vane. When you loose either of those forces, the governor spring tension DECREASES on the carb throttle plate, and the carb plate opens a LITTLE MORE to allow the engine RPM to increase back to your original selected throttle setting

I might be over running your reason for asking this but do not confuse governor action with "hunting" of engine RPM's due to partially blocked gas delivery pathways in the carb

Matt, any "feedback system" in electronics or mechanics can be a simple device or a simple connection but can be very difficult to fully understand. As Wallfish stated, MANY DIFFERENT FORCES ARE IN PLAY AT THE SAME TIME - ALL WORKING AGAINST EACH OTHER - AT THE SAME TIME.

Read as much as you can about it - from any source possible -sometimes just 1 more read may be the key to finally "getting it."

[rmaynard 14,976]

As simple as I can make it, here is my understanding of the role of the governor.

The throttle cable does not hooks directly to the carburetor. It hook indirectly by way of the governor linkage. When you set the throttle on the dash, you are setting engine speed via the governor linkage, to allow the engine to run at no less than the speed selected. As you start to pull up a hill or under a load, the fly-balls in the governor cause the linkage to open the throttle plate in the carburetor to keep the tractor running at a preset speed. However, it will not cause the engine to run at more than 3600 RPM +/- (as set by the throttle limit). Once the load decreases, the governor linkage reduces the throttle back to the preset position that you selected via the throttle lever on the dash.

It will not slow the engine any less than where you set the controls on the dash.

Bob

[mattd860 162]

Ok I got it now. These are exactly the explanations I was looking for. I suspected that the fly weights closed the throttle a little bit under normal operation to reach equilibrium between the flyweights and spring tension. But this was only a suspicion until you guys confirmed it .

Now I just have to find the correct governor spring since the factor one has been discontinued with no substitutes....

[Coadster32 793]

Glad you got it, and hope I didn't come off snippy. (been a long day). Govenors can indeed be tricky.

[WheelHorse_of_course 99]

And an anecdote to complete the "lesson".

I bought a tractor and noticed that there was a governor issue as I could rev it too high. This did not bother me too much as I could tell "by ear" and keep it in the safe range.

However I found it very hard to use the tractor as I would go up a slope (or hit a heavy patch of grass when mowing) and I would have to increase the throttle. Bt then the engine would rev too high when I got on level ground (or normal grass) and I'd have to adjust it downward. To keep from stalling/bogging down or over revving required constant attention.

When I looked into it I found the throttle cable was simply connected to the wrong point and when I connected it properly all was good.

:thumbs:

[W9JAB 156]

Replying to Role of the Governor????

In Illinois it's trying to stay out of Jail!

Three former Illinois governors have gone to prison in the past 35 years, and a host of other governors have gotten into legal trouble.

:wh:

[mattd860 162]

LOL. Can Illinois politics ever be saved? We'll see after this election but I have my doubts.

[squonk 39,290]

Replying to Role of the Governor????

In Illinois it's trying to stay out of Jail!

Three former Illinois governors have gone to prison in the past 35 years, and a host of other governors have gotten into legal trouble.

And here I thought the Governor's job was to raise taxes and give his buddy's kids jobs!! :)