Kohler Help:

Hello,
I am looking for some advice/help for an engine problem I can't seem to figure out.
Kohler CV20S (20hp twin) Spec 65522. Engine is on a Toro 62" cut walk behind mower. It's been this way for quite some time but this year it's bugging me enough to address it... Engine surges unless you run the choke 3/4 closed. With choke shut she's a mowing mo'chine, you open the choke it will run but spits back through the carb while running and surges and will eventually quit. It will never crank back hot or cold unless you choke it (normal kohler?) To date I have dis-assembled the carb, soaked (in gunk cleaner in the gallon can) over night blowed out using compressed air, then used a can of carb/choke cleaner and blowed it out again before re-assembly. New air filter with pre cleaner. I was thinking it's starving for fuel (since it runs fine choked) so I just installed a new fuel pump and even ran it without the fuel cap and it's still doing the same dang thing. It spits like its trying to clear its self but there shouldn't be anything in there.... I even sprayed cleaner around the carb with it running to check for a leak and no engine change. Ideas? and Thank you for your time,

Wayne

Many times you can clean a carb and spray it out with carb cleaner but that is not enough to remove small pieces of rust/dirt from passage ways. You need to use a small wire or as I use a torch tip cleaner tool and poke out all the passage ways then spray out and do that 2 or 3 times

Maybe so, I didn't mention in orginal post that there is a jet on top of the carb and turning it in till it stops has no effect on the motor running. You're thinking it's still a blocked passage? [/quote]

What Old said is gospel! Everyone should have a torch cleaner in their carb tool kit. They are made to clean small holes without damage.

Also, check the intake manifold for air leaks. That will also cause a lean mix and symptoms like yours. I spray carb cleaner around all the gaskets when it's running. If there is a leak it will be obvious.

Put a vacumn gage on it , valves may need adjusting
or work , warped, sticking ect

When you put on the new fuel pump, did you crank the engine with the fuel line off the carburetor, and note that it was actually pumping fuel? Not drip, drip, drip but a nice solid stream?

First check the plug wires. If they are OK.

Remove the Carb.

Located the green ground wire from the carb to the engine.

Where the ground wire attaches to the engine. Run another ground wire from that screw to a good ground on the frame.

You should end up with two ground wires attached to the same screw on the engine. One to the carb. One to the frame..

You can come back and thank me later.. :wink:

If you have a carburetor, the main adjusting screw probably needs to be opened. Hal

Just an update. I took the fuel line off and turned the engine over and fuel delivery is full stream. So, I took everything back apart and pondered and puzzled then I think I found it..... remember I bought this used many years ago and just always run it till it got to me this year. The idle mix jet has been cranked down to the point that the tip broke off in the hole.... I've tried to extract it but not been successfully done at this time. Guess I got 2 options. Continue running it with the choke issue. Or findividual another carb. I don't think trying to drill it out is an option cause its aluminum carb and brass jet and there is no way to see down in that hole to make sure you're drilling the broke jet and not carb body. Then it would be a no win all together. At least right now it will run as long as the chokes down. I can't believe that tiny little hole can cause this much trouble lol. I'm going to try and use a pick or something like that to try once more to extract it..... thank you everyone for the replies. I'm open to ideas on it or maybe I can find a carb somewhere. .... thank you again

Wayne

get numbers and type off carb i have 5 gallon buckets full of used carbs off various motors if
that would help

Under the nikki on the carb it has 3. Under where the idle screw adjustment is there is a little flat plate with 620 28-431 and under that it says made in Japan.....

More or less sounds to me like it needs the Governor arm re-positioned..if out of adjustment, they run really badly..