Kohler Courage XT-7 multiple stalls when cold

[theoldwizard1]

The engine mounted on a Ariens 21" walk behind and is 2 years old. Used VERY little.

I have replaced the carb due to "other" issues.

Now that cooler weather has moved in, the engine starts easily (after 3 pumps of the primer) but stalls almost immediately. 3 more pumps, fires, stalls. The only way to keep it running is to pump the primer before the engine stalls. After 30-60 seconds of this, it will run fine.

Any suggestions on how to keep it running for the first 60 seconds without having to hold the shutoff bar and stretch to pump the primer ?

 

[Lawnranger]

It sure sounds like the carburetor cannot keep up with the need when the engine is cold and since your carburetor is a primer, not a choke, you have no other way to add extra fuel in addition to pumping the primer. I am going to post a few points that I'm sure you have already checked but here goes. I have had people bring equipment to me that will not start and I drain the old fuel, replace the carburetor and any other needed items, add fresh fuel and the machine runs great. I return the equipment to the owner and they use it until it needs to be refueled. They refuel it and they bring the equipment back saying all kinds of ugly words about me and their equipment as to why it will not start only to find out that the fuel in their fuel container is from last year and has gone bad. I then ask them how that crow tastes. Actually, I only think of saying that and I educate them on the need for fresh fuel and I get to charge them again for the additional needed work. So, I'm going to ask you the same question, are you absolutely sure the fuel is fresh? By fresh, I mean 30 days or less. If so, then are you absolutely sure the replacement carburetor is an exact match of the previous one? If so, is it possible the factory messed up and put the wrong jet in the replacement carburetor? Did you remove the bowl (if equipped) from the carburetor and have a look for any contamination?

Were the carburetor mounting surfaces absolutely clean and did you use new gaskets? It is possible an air leak exists causing a lean condition when the engine is cold?

Please tell me what the "other" issues were for replacing the original carburetor.

Do you use any fuel additives such as a fuel stabilizer?

It sounds like there is a fuel restriction somewhere preventing the proper air/fuel ratio for cold start operation. Have you tried pumping the primer six times and starting the engine cold? How about eight times? How about more than eight times? What were the results?

If you will answer all the questions I have asked, we will narrow down the possibilities as to what is causing the problem you are experiencing with your mower.

At this point the cause of the problem could be a lot of things and even something I haven't mentioned yet so I am starting with the basics and doing the best I can with the limited information you provided.

Take your time in checking things out and report back with your findings when you are able.

 

[theoldwizard1]

It sure sounds like the carburetor cannot keep up with the need when the engine is cold and since your carburetor is a primer, not a choke, you have no other way to add extra fuel in addition to pumping the primer. I am going to post a few points that I'm sure you have already checked but here goes. I have had people bring equipment to me that will not start and I drain the old fuel, ...

Fresh fuel. Inline filter "seems" clear (back flushed with spray carb cleaner)

Were the carburetor mounting surfaces absolutely clean and did you use new gaskets? It is possible an air leak exists causing a lean condition when the engine is cold?

Mounting surfaces clean. Carb came with new gasket.

Please tell me what the "other" issues were for replacing the original carburetor.

Needle sticking in seat. No rebuild kit available. I read elsewhere on this board this was common and that Kohler was replacing carbs on machines under warranty. Replacement carb was less than $40.

Do you use any fuel additives such as a fuel stabilizer?

SeaFoam

It sounds like there is a fuel restriction somewhere preventing the proper air/fuel ratio for cold start operation. Have you tried pumping the primer six times and starting the engine cold? How about eight times? How about more than eight times? What were the results?

Six for sure. I don't think it ran any longer.

Re: Fuel restriction. Wouldn't that cause lack of power when running ? Engine runs strong once warmed up.


(P.S. been messin' with small engines for "awhile" :biggrin: )

 

[Lawnranger]

Re: Fuel restriction. Wouldn't that cause lack of power when running ? Engine runs strong once warmed up.


(P.S. been messin' with small engines for "awhile" :biggrin: )

Since you been messin' with small engines for "awhile" :biggrin: then you probably know that a cold engine needs more fuel to operate properly until it reaches operating temperature (hence the need for a choke or primer) and that is why I say there "could" be a restriction and the result is that you have a "lack of power when running cold" but not so much of a restriction for normal operating temperature. Simply put, the carburetor is not supplying enough fuel to operate a cold engine and you need to determine why the carburetor cannot perform its job or where the lack of fuel problem is located.

Since you are the eyes, ears and fingers in the situation you will have to do more diagnostic work and all we can do is give "possibilities" based on logic and experience as to the cause. A new part does not always mean a good part i.e. carburetor. Since Kohler has a known problem with the carburetor on that particular model it's possible the replacement is no better and you'll have to pump the primer to keep the engine running until it warms up enough to run on its own. I know that is not the answer you want to hear but if everything else checks out, what else can you do?

Did you check for an air leak between the carburetor & engine by spraying a shot of carburetor cleaner around the connecting point while the engine is running? If engine R.P.M. changes when you perform this test an air leak is most likely the culprit. Leave no stone unturned.

 

[theoldwizard1]

... Simply put, the carburetor is not supplying enough fuel to operate a cold engine and you need to determine why the carburetor cannot perform its job or where the lack of fuel problem is located.

And I also know that today's non-adjustable carbs are designed to run as lean as possible in order to meet CARB and EPA standards.

Did you check for an air leak between the carburetor & engine by spraying a shot of carburetor cleaner around the connecting point while the engine is running?

Worth a check.

 

[theoldwizard1]

I could not find any air leaks.

I have used the mower a couple more times. You have to pump the primer about every 5-10 seconds until the engine warms up (about 1-2 minutes), but after that it runs fine. Restarts may require one primer pump.

Other than that, it seems to be a good engine/mower.

 

[theoldwizard1]

New development.

Primed it 3 time today and it started right up AND DID NOT STALL !!

Maybe just a long breakin on the engine/carb ???

 

[chance123]

And I also know that today's non-adjustable carbs are designed to run as lean as possible in order to meet CARB and EPA standards.

CARB? in "your" state? I think that is California only (California Air Resources Board)
They are a nightmare for the landscapers and shop owners, as can be the EPA

 

[theoldwizard1]

CARB? in "your" state? I think that is California only (California Air Resources Board)
They are a nightmare for the landscapers and shop owners, as can be the EPA

CARB usually comes up with the crazy ideas and EPA just follows along.