425 Problem

[SnowRidge]

Went on to the Kohler web site and clicked on problems and got connected to expert who gave this advice.

This is where you have to decide if the problem is in the engine or the transaxle. If the engine rpm stays pretty much constant, then I'd look at the motion belt system first. If the engine bogs down hard, like it's struggling to pull, then I'd look at the braking system first. If the engine loses a few rpm but doesn't seem to be straining, then I'd go to the transaxle. If the engine sounds loose, like it wants to over-rev or blows black smoke then pull the spark plugs and check their condition. If the engine just sounds weak, you may have a fuel delivery problem.

Personally, just from what you have described so far, you may have a transaxle that's not cooling. Check that the fan is in one piece and that the transaxle is clean. That fan is essential for the Hydrostat to work and grass built up on the unit can also allow too much heat to build-up which thins the oil in the transaxle.

Thought I would pass this info along for your input as well.
PJ

That information is useless. Their "expert" system thinks your Kohler engine is powering a belt driven hydrostatic transaxle in a lawn tractor.

 

[Gravy]

I'd have to say that it sounds like that Kohler expert is well-intentioned but doesn't have a CLUE about how a PT works. Talking about belts and hydrostats applies just fine to a typical SCUT, but for a PT, well, not so much.

Unless your previous flooding problem caused unusually extensive engine/compression damage, I'd guess that Something Is Not Right with your carburetor - wrong adjustments, wrong parts, linkage problems, etc. It was working OK until it flooded. Unless you've changed something else, the carburetor is the only thing that isn't the same as when it was running fine.

One consistent thread through my auto mechanic career was that if it's not running right, start by rechecking whatever was worked on last.

 

[Marks481]

It sounds to me like their "expert" is a computer program that just regurgitates pieces of their FAQ in response to a "dirty word search" performed on customer inputs.

Which is an annoying way to do business. I think Amazon does the same thing; email to customer service will repeatedly generate responses that almost... but not quite... have something to do with what you emailed them about.

 

[MossRoad]

I'd take the tractor to the shop and have them check the carb while it is attached to the engine.

 

[pajoube]

I'd take the tractor to the shop and have them check the carb while it is attached to the engine.

That is probably the best advice.
This is the latest advice from Kohler
If this has the electronic governor, it has to be re-installed in a particular way. Below is the instructions copied from the Kohler manual.

Adjustment Procedure
The DLA must be in the fully retracted position during
assembly. The full range of throttle plate movement will
not be achieved if the DLA is partially extended when
assembled. Loosen the two DLA mounting plate
screws located on the top of the actuator plate. With
the throttle linkage centered in the U-Clip at the end of
the DLA shaft, slide the DLA bracket assembly back
until the throttle plate is fully open. Torque the
mounting plate screws to 2.5 Nｷm (22 in. lb.).

The DLA is the Digital Linear Actuator, the device that moves the governor rod. If you don't have the electronic governor, then we need to look at something different. But if you do, this could easily be the problem as the throttle won't fully open unless it's reset when the carburetor is installed.

 

[SnowRidge]

That is probably the best advice.
This is the latest advice from Kohler
If this has the electronic governor, it has to be re-installed in a particular way. Below is the instructions copied from the Kohler manual.

Adjustment Procedure
The DLA must be in the fully retracted position during
assembly. The full range of throttle plate movement will
not be achieved if the DLA is partially extended when
assembled. Loosen the two DLA mounting plate
screws located on the top of the actuator plate. With
the throttle linkage centered in the U-Clip at the end of
the DLA shaft, slide the DLA bracket assembly back
until the throttle plate is fully open. Torque the
mounting plate screws to 2.5 Nｷm (22 in. lb.).

The DLA is the Digital Linear Actuator, the device that moves the governor rod. If you don't have the electronic governor, then we need to look at something different. But if you do, this could easily be the problem as the throttle won't fully open unless it's reset when the carburetor is installed.

You should have the same engine as me. The governor is mechanical, and the governor spring must be installed correctly. Check page 5.22 of the PDF I linked, and see if your setup looks like the one in the drawing. If it does, check to see if the spring is correct.

 

[pajoube]

PJ, If you pull the choke out a little does it make any difference? I have used the 20, 22, 25 HP Kohler's, on my Dixie Choppers, and keeping the fuel solenoid clean, and water in fuel was about my only problem. Recommend you take it out and clean it . Maybe the service guy did it for you .

Sorry to get back to you so late. I have been unable to get much done these past few days. I mowed today (slow) and tried the choke but all it did was want to die. I plan on taking the tractor to the Kohler dealer tomorrow to see what they find. To be frank, I do not think they are the brightest bunch around.
PJ

 

[MossRoad]

Well, then... best of luck with that!

 

[Charlie_Iliff]

Sorry to get back to you so late. I have been unable to get much done these past few days. I mowed today (slow) and tried the choke but all it did was want to die. I plan on taking the tractor to the Kohler dealer tomorrow to see what they find. To be frank, I do not think they are the brightest bunch around.
PJ

Paul:
This and your running out of gas early suggest you're running rich, not lean. Also consistent with no bucking or backfiring. Rich mixture just reduces power, but usually runs smoothly.
I don't know your carb, but at your altitude the main jet should be smaller than at sea level. If they replaced it, they might have gone to sea-level stock. Another possibility is the float again. If it doesn't quite shut off flow, it can make it run rich. They may not have gotten it right.
Good luck.
Charlie

 

[pajoube]

Paul:
This and your running out of gas early suggest you're running rich, not lean. Also consistent with no bucking or backfiring. Rich mixture just reduces power, but usually runs smoothly.
I don't know your carb, but at your altitude the main jet should be smaller than at sea level. If they replaced it, they might have gone to sea-level stock. Another possibility is the float again. If it doesn't quite shut off flow, it can make it run rich. They may not have gotten it right.
Good luck.
Charlie

Back from the dealer today. Have not had a chance to run with mower as its snowing.
They said it was bad plugs and air cleaner. Will test out tomorrow if possible. I have a bad feeling about those guys.
PJ

 

[MossRoad]

Snowing! I was fishing in a T-shirt Tuesday night.

 

[SnowRidge]

Snowing! I was fishing in a T-shirt Tuesday night.

Ya think?

 

[pajoube]

Well, today I mowed and tested the new plugs and air filter out. That did not help at all.
What I have found is the following:

Not just under load (pto) but now its all the time when working.
It gets hot and starts to bog down
Turn off for about 10 minutes and runs great until hot again.

I still can not get out of my head that its got to be the carborator. If its not getting enough fuel when under load is there an adjustment of the float?

I down loaded the Kohler engine specs that SnowRidge sent.
PJ

 

[SnowRidge]

Sounds like it may be gradual fuel starvation.

Check for a clogged tank outlet or fuel filter. A lot of us have had crud accumulate in the elbow. Whoever builds these tanks for Power Trac is pretty sloppy about cleaning the manufacturing debris out. The alcohol in the fuel also loosens up any excess sealant in there.

Also check to make sure the fuel tank cap vent isn't blocked.

 

[MossRoad]

Had a problem with carburetor float sticking so ordered a carb kit and had the local Koehler dealer install the kit.
Went to mow and found I was unable to get full power when under load. All else seems ok but rpm's seem little low. In checking the manual there is no adjustments for this carb. I did adjust the throttle linkage but that did not seem to help.
Did mow today but still not at full rpm's when under load so mower is sluggish and going up incline very slow.
Not sure what to check any more, any suggestions?
PJ

Well, today I mowed and tested the new plugs and air filter out. That did not help at all.
What I have found is the following:

Not just under load (pto) but now its all the time when working.
It gets hot and starts to bog down
Turn off for about 10 minutes and runs great until hot again.

I still can not get out of my head that its got to be the carborator. If its not getting enough fuel when under load is there an adjustment of the float?

I down loaded the Kohler engine specs that SnowRidge sent.
PJ

Let's go back to the original problem... you had the float sticking and you ordered the carb kit and had the Kohler dealer install it.

How did you diagnose the float was sticking?

 

[J_J]

pj,

Did you say that your carb was an adjustable carb, and that you ordered a fixed jet kit for it? Did they return your old parts? Have you had a chance to remove the fuel bowl and see if the fuel flow is good. In setting the float, you turn the carb upside down, and the distance from the float to the rim of the carb is stated in the kit/manual. If it is a brass float, you bend the tang. If plastic, it might need some heat.

 

[pajoube]

Let's go back to the original problem... you had the float sticking and you ordered the carb kit and had the Kohler dealer install it.

How did you diagnose the float was sticking?

Had fuel in the oil, dripping out of the muffler, all indications of stuck float.
PJ

 

[pajoube]

pj,

Did you say that your carb was an adjustable carb, and that you ordered a fixed jet kit for it? Did they return your old parts? Have you had a chance to remove the fuel bowl and see if the fuel flow is good. In setting the float, you turn the carb upside down, and the distance from the float to the rim of the carb is stated in the kit/manual. If it is a brass float, you bend the tang. If plastic, it might need some heat.

This is not an adjustable carb. Kohler ordered kit to replace parts in same type of carb. When I installed carb back on tractor there were few parts to put back together and very easy.

 

[MossRoad]

Had fuel in the oil, dripping out of the muffler, all indications of stuck float.
PJ

O.K.

So now after the carb kit was installed by the Kohler dealer the machine gets hot quickly and loses power. Appears to be a symptom of running lean, correct?

 

[Marks481]

maybe OT, but I ran out of gas today. I was surprised when I refilled the tank that it did not self-prime the fuel line.

The reason was is the way the fuel line is looped, and the very small diameter prevented the air trapped in the line from flowing out. I ended up having to squeeze all the air out of the line, and mess around with the filter to get most of the air bubble out of it. Possibly something is caught in that little elbow on the tank (although I can't see anything), cause I couldn't get the last bit of air out.

I think a straight nipple attached to the tank and a new larger diameter hose are in my future.