Kohler engine surging

[zufrieden]

I took out dad's Gravely from winter storage, sharpened the blade and started cutting grass. It was running smooth, then about 5 minutes in, the rpm started surging. It idles just fine. It surges anywhere above idle. If I hold the throttle on the carb, the engine smooths out and just hums. I am assuming this is a problem with the governor, but have no idea where to start. I can't find a thread on this, so I must not be selecting the correct search parameters.

It is a Gravely 5260 according to the hood, I could not find any other plates on it. The engine is a Kohler

Model K181S
Spec 30675D
Ser # 8250569

Thanks in advance for the help.

[ATLANTICCENTRAL]

Originally Posted by zufrieden

I took out dad's Gravely from winter storage, sharpened the blade and started cutting grass. It was running smooth, then about 5 minutes in, the rpm started surging. It idles just fine. It surges anywhere above idle. If I hold the throttle on the carb, the engine smooths out and just hums. I am assuming this is a problem with the governor, but have no idea where to start. I can't find a thread on this, so I must not be selecting the correct search parameters.

It is a Gravely 5260 according to the hood, I could not find any other plates on it. The engine is a Kohler

Model K181S
Spec 30675D
Ser # 8250569

Thanks in advance for the help.

Before you condem the governor, clean the carb in place and check all the carb settings. And engine that is too lean or too rich will "hunt", especially too lean.

Sheldon

[arcam8123]

Like Sheldon said, most surging is a carb issue. If you close the choke some, does it have an effect on the surging?

[Grand Sierra]

Hunting or surging can be fuel or air. Yours is probably fuel related, I fixed my generator that ran better on half joke carb bowl had junk and water in it. I just cleaned bowl didn't take it apart ran Seafoam in it for an hour. It still hunted after bowl cleaning let it sit a few weeks and its running great now, I was surprised it cleaned everything out.

[Richard-tx]

I suspect water contamination. Check the fuel. If it is yellow, then it likely has water in it. The problem with water is that even though the engine may run fine, there can be a layer of water lying in the bowl just below the main jet of the carb corroding it.

Some carbs have a bowl drain. THe Kohler K series do not as a rule.

The fix for water contamination is to drian the tank, blow it out dry, flush the lines, replace the fuel filter or clean sediment bowl, and then clean out the bowl of the carb. If the water has reached the main jet, then a full carb cleaning may be necessary.

[zufrieden]

Thanks Guys, I will try these things tonight and let you know.

[CTPhil]

With gas being how it is, I've started the habit of treating every small engine that's not running right with an additive like seafoam before getting out any wrenches. It worked wonders on my 5460.

[Richard-tx]

As far as I am concerned Seafoam is a ripoff. Read the MSDS for the reason why. In any case, I don't use it. If you want to, then by all means do so. Why should I care one way or the other? It is your engine, not mine.

Lighter Fluid is another example. I see that stuff usually selling for $9 or more for 12 ounces online. Lighter fluid is 100% VM&P Naptha. I buy VM&P naptha for about $15 a gallon from the paint store. The rest is packaging, advertising, and profit.

Charcoal lighter is yet another example. It is nothing more than Mineral Spirits.
http://msds.walmartstores.com/cache/27928_1.pdf

I love MSDS data. It really brings out the truth in specialty products.

[Grand Sierra]

It worked great on my weed wacker that bogged out at full throttle, ran it threw the tank and it reved like crazy. So far I have had good luck with it next my Honda powered 2 stage Dewalt gas compressor is running a little off. I'll see if I can go 3 for 3. I do like to take carb off and clean out everything but if I'm not in a rush for something I'll drop bowl and add it in fuel tank so far it has worked for me.

[zufrieden]

I changed the fuel, took the bowl off and took all the water and rust particles out of it. Cleaned things up with some carb cleaner. She started up and still surged a little. I made a small adjustment to the high speed mix and she is running great. Thanks for all the help guys.