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rbig
06-11-2005, 12:11 PM
The breather on the K-532 seems to be an external part of the governor (at least the breather valve housing is).

How does the breather functionally interrelate to the governor?

Where does the crankcase breather ultimately vent to?

There is also a breather connect to the carb. Are crankcase exhaust gases split between the governor and the carb?

The manuals provide inadequate clarification of the above for me.

fixer67
06-11-2005, 02:27 PM
On newer engines all crankcase gases are vented back into the carb to be burned. On older engines it was not uncommon for the crankcase gases to be vented straight out into the air. Now the EPA says they have to be vented back into then carb to be burned. I am thanking the crankcase breather has nothing to do with the governor. I will have to check a K-532 IPL but I am thanking they just happen to be in the same general area is all.

rbig
06-11-2005, 02:43 PM
}}} I am thanking the crankcase breather has nothing to do with the governor. I will have to check a K-532 IPL but I am thanking they just happen to be in the same general area is all. {{{

I think you're right. That was my initial conclusion, but I'm no expert.

Assume you're right. The next question is: where does the breather pipe vent to? The manual tells me there is a connection to the carb, which is supposed to provide a vacuum effect for the crankcase. OK, fine.

But, what about if you had ring wear and blowby that needed a place to get out? Do all the crankcase gases flow out through the carb? Or, is there another vent path I'm not seeing?

fixer67
06-11-2005, 02:59 PM
OK. Post spec number for me. Most do not hook up to the carb it's self but to the air filter housing. And if you do have a lot of blow-by it will blow oil into the air filter housing and into the carb and then be burned fouling the plugs. On older engines it just vented out on to the ground. You always had a wet oil spot on the engine or frame. Now days the EPA says that is a big NO-NO and it must be returned to the engine to be burned. If you have ring ware bad enough to cause blow-by being vented back into the intake to cause a problem with the engine running you need to replace the rings. The carb does not provide a vacuum for the crankcase. The vacuum comes from the action of the piston going up and down.The breather vent has a one-way check valve in it that lets the pressure vent but does not let air back in when the piston goes up creating a vacuum in the crankcase. The only reason you want a vacuum in the crankcase in the first place is to vent bllow-by and to prevent oil from being pushed out of the crankcse by heat and blow-by. Post spec numbers of the engine. K-532 is the model I need the spec numbers to be able to help any more. This engine came out with more styles of air cleaners and carbs than I can count

rbig
06-11-2005, 03:38 PM
}}} This engine came out with more styles of air cleaners and carbs than I can count {{{

You are so right about that. The model is QS (i.e., K-532QS), and the spec is 53131.

fixer67
06-11-2005, 06:09 PM
I read the K-532 manual and I see why you said what you the way you did. The wording is a little miss leading about the breather tube going to the carb.
Below is a photo that may help you out. I should have known this was on a John Deere.

rbig
06-11-2005, 08:13 PM
My air cleaner shroud isn't round like the one depicted. Both serve the same function, though. I'll check mine to see if there's any kind of hose connected to it from the breather valve housing. Seems like there'll have to be.

Thanks for the info.

freddyc
06-11-2005, 09:28 PM
I have a 20hp Kohler and the crankcase vent tube goes straight into the air cleaner housing (inside the air filter). I must have blow by because the bottom plate that the air filter sits on is covered with oil after only a few hrs running.

If I leave the air filter out for a while, it doesn't seem to vent as much oil / vapor as it does with it in there. If I put my finger over the end of the tube I can feel a small pulsing.


I was told also that if you either overfill the engine oil or do odd angle work (tilted motor) then the same thing happens also.

Restrorob
06-11-2005, 10:03 PM
I have a 20hp Kohler and the crankcase vent tube goes straight into the air cleaner housing (inside the air filter). I must have blow by because the bottom plate that the air filter sits on is covered with oil after only a few hrs running.

If I leave the air filter out for a while, it doesn't seem to vent as much oil / vapor as it does with it in there. If I put my finger over the end of the tube I can feel a small pulsing.


I was told also that if you either overfill the engine oil or do odd angle work (tilted motor) then the same thing happens also.

How about posting your model and spec. numbers,I remember seeing a couple breather updates Kohler put out on a new style breather assembly for the 20 and 22hp engines,This just mite be the fix for your problem.
BTW How many hours are on this engine ?

rbig
06-11-2005, 10:26 PM
My manual says that somehow the carb is supposed to supply a vacuum on the crankcase through the breather. To me that means that the crankcase gasses go into the carb, if it's being used to put a vacuum on the crankcase.

Assuming that's true, I'm still not sure why the oil in the crankcase is so easily siphoned by the breather port down there.

One of the things that needs to be checked out (and I'll get to that next week on mine) is whether or not the one way valve is working properly. I'm further assuming that if it's not, then it may contribute to the oil getting through the carb into the combusion chambers.

rbig
06-11-2005, 10:43 PM
What a mechanic acquaintance just told me:

The vacuum on the crankcase is to prevent oil being forced up past the seals.

In some ways, this makes sense. If oil was being forced up, and past the seals, then it would account for the smoking when it's burned in the combustion chambers.

I still have a problem, though, in that I didn't know our Kohler twins have valve stem seals. If they don't, then the crankcase vacuum is even more important.

All this means that if the valve sticks shut, the carb can't put a vacuum on the crankcase, and it would be more suseptible to forcing some oil up. And, if there aren't any valve stem seals, then that adds to the problem.

This just might be whats causing our oil in the cylinders problems.

I'm going to hit the books again and see if I can find out for sure if my Kohler twin does have valve stem seals like many OHVs I've worked with.

freddyc
06-12-2005, 05:00 PM
How about posting your model and spec. numbers,I remember seeing a couple breather updates Kohler put out on a new style breather assembly for the 20 and 22hp engines,This just mite be the fix for your problem.
BTW How many hours are on this engine ?


The model # is CH 20-S
I think theres also a number of 64509 on it.
I believe the serial # is 9232207007

Its an old motor... early 90's I believe and I don't know how many hours... I got it used.

rbig
06-13-2005, 12:44 AM
I went out today (caught a break I didn't think we'd have; Arlene moved right on through and was a big wimp, too) and took my air breather valve assy off. The valve unit seems to be jammed shut (I couldn't open it or remove it without going for bigger tools).

Adding to what you told me and what I've discovered about my engine, I think I've fairly well pieced things together. And, of course it doesn't have valve stem seals. I simply forgot it was a flat head. Senior moment there......

First, I'll be putting in a new air breather assy tomorrow, and a new air filter

And yes, I did find oil in the air filter.

Background for this is the K-532. As you say, it's a flathead, therefore doesn't have oil seals on the valve stems. Because of this, it's easier for oil to get forced up past the valves into the cylinders where it's burned.

I started my problems with an overfilled oil supply. The tractor started puffing out oil smoke when I'd mow down and up culverts, and get sideways on a slope. Didn't do it previously. This lead to me finding out about the accidental overfill.

I corrected that problem by draining out my oil (needed a change anyway), and putting a new filter and new oil in----carefully measured.

I now think I had two closely spaced, separate, but related problems, the first being the oil overfill.

Next, I started getting puffs of oil smoke while bumbling along on the straight and level. The RPMs would drop a bit, smoke would come out, and then the situation would clear, and RPMs would go back up. It did this repeatedly and cyclically.

Obviously, if my crankcase isn't overfilled, there is some other problem. This lead to a hunt for possibilities.

Seems my engine has a one-way air breather valve which is inline between the crankcase and the carb throat.

Here's where it gets interesting. Turns out the air breather is an integral part of the governor. Apparently the airflow is from the crankcase, through the governor, on up to the carb throat.

The purpose of the breather going to the carb is for the carb to provide low intensity vacuum to the crankcase to keep pressure buildups there from forcing oil up past the valves.

So, if this air breather valve sticks shut, it would result in pressure buildup in the crankcase, which would lead to oil getting forced up past the valve stems (no other path, other than blowing the dipstick cover off, and it's not doing that).

Of course, any high op hour wear around the valve stem area in the block would make the susceptibility to oil getting past the stems all the greater. I don't know in my engine if this area was worked on during a recent rebuild (approx 50op hrs ago) or not.

The reason I'm backing away from excess vavle guide/passage wear as being a cause of my problem is because I believe that, if excess wear was a cause, then I think I'd see continuous smoking, and that's not the case.

Anyhow, the thing now is to put a new air breather valve in tomorrow, as well as new air filter, and see how things go. I hope this fixes the problem, because if it doesn't, I'm out of theories and ideas of what to do next.

Incidentally, I'm really thankful for this forum I'm in and the great folks who try to help others.