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I have a Toro zturn with a Kohler command pro 23hp dual OHV. It will startup, with the idle set at low only, and runs rough. if you try to idle up or use the choke it immediately stalls. i pulled off the air cleaner and if you hold your hand in front of the carb intake it will get wet with gas spraying out. i pulled the carb and cleaned it and put back on with no change. it was pretty clean. the valves are hydraulic, with no adjustment. i pulled the valve covers and spun the engine just to make sure that all was intact. any ideas on what to check next ? thanks

At low speeds the automatic decompressor opens the inlet to decompress /
Start the engine then manually open the throttle by pushing the govenor arm

it stalls immediately when I manually move the throttle lever.

Do the quick test.
Unplug one spark plug wire, and try to start.
Then try it the other way around.
If it runs on one side and not the other, that will narrow it down.
You may have an intake valve not fully closing, or the like.

Is there a chance that the fuel solenoid on the carb isn't opening. On Kohler carbs the solenoid shuts off the high speed main jet but not the idle circuit jet.

I removed the fuel solenoid and it is working correctly with the piston sucking in with the key on.
I removed the spark plug wires one at a time and didn't notice a difference. It's to the point now where it starts and chugs for a few seconds and dies. It is misting gas out the carb when running and there is constant pressure out thru the exhaust, not a chug...chug....chug

Could also be the possibility of the float valve not sealing and the fuel pump is overfilling the carb when running, spitting out the extra fuel.

Empty out the gas totally, then start and run the engine. Run it until it runs out of gas and dies from that. See if it starts running better there at the end, to see if it is a carb problem.

Is it black smoking when it's dying.

Fish said:

Empty out the gas totally, then start and run the engine. Run it until it runs out of gas and dies from that. See if it starts running better there at the end, to see if it is a carb problem.

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Was thinking water in the gas too. Experience has taught me to drain several ounces gas from the entire tank fuel line during all carb cleanings.
It's a bich to R & R a carb, only to find water still in the lines.

Yeah, that water likes to sit in the bottom of things, and is hard to get rid of totally.

I have seen Briggs with a bad cam run poorly, and tend to spit out gas.

took it to a shop and they found that the exhaust was almost plugged solid. They pulled the screen out from the end and there was alot of black carbon chunks packed in behind it.

dlang10538 said:

took it to a shop and they found that the exhaust was almost plugged solid. They pulled the screen out from the end and there was alot of black carbon chunks packed in behind it.

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Yep, won't run good with the EX plugged up. When an engine won't run or won't run right, the cause can be MANY. It is hard and sometimes impossible to diagnose over the internet, but several of us try. It takes HANDS ON to do the real repair!
Glad you got it fixed!

you got some good advice above....i'm going to suggest the simple first.....do you use gas with 10% ethanol?
I'm in the wholesale gas business and we are mandated to blend this ethanol into gas.
It's hygroscopic...meaning it absorbs moisture like a sponge and turns gas bad in 90 days.
My Kohler Command 25 started sputtering / backfiring - especially going up hills and a nice back fire when i turned it off in the garage .
Cleaning the carb with Techron only solved the issue for so many days. Never really a long term cure.
So ethanol is a byproduct of corn....it turns into a black crud in your carb and will rust it out in time.
If you catch it in time there is a solution i found in gas stabilizers.
It works differently. Keep in mind with ethanol blended gas in your thank.....the vent hole in your gas cap is literally sucking moisture out of the humid summer air and storing that moisture / water in your gas and that ' interaction' of water with fuel is turning into a crud inside the carb.
What did I do.
I talked to a guy who use to rustproof the bridges you drive over. He also invented the ' label less. - label' first used in Haines Underwear. It's that print in the cotton that will outlast the cotton itself. He's a creative guy. He has a product called CERMA FUEL TREATMENT. Why use this? It's a different kind of fueler stabilizer. He simply ' splits' the H2o or ( the water molecule) with his treatment. In other words the Hydrogen molecule no longer bonds with the O.....What we know the components in water or H2o is split apart and it's no longer ' water' or H2o. The Hydrogen becomes a very mild octane boost but nothing you will notice and the " O" just goes out your vent hole into the air. The water interaction which is the downfall of ethanol blended gas is halted. After 8 hours of heavy use, my Kohler 25hp stopped sputtering...backfiring and has been running smooth for 2 years straight. I got to my carb before the ethanol rotted it out. Dunno if you'll be that lucky. If not...when it get it . fixed and I suspect maybe a new carb might be down the road.....use this Cerma Fuel Treatment. I bought t

blairbuc said:

you got some good advice above....i'm going to suggest the simple first.....do you use gas with 10% ethanol?
I'm in the wholesale gas business and we are mandated to blend this ethanol into gas.
It's hygroscopic...meaning it absorbs moisture like a sponge and turns gas bad in 90 days.
My Kohler Command 25 started sputtering / backfiring - especially going up hills and a nice back fire when i turned it off in the garage .
Cleaning the carb with Techron only solved the issue for so many days. Never really a long term cure.
So ethanol is a byproduct of corn....it turns into a black crud in your carb and will rust it out in time.
If you catch it in time there is a solution i found in gas stabilizers.
It works differently. Keep in mind with ethanol blended gas in your thank.....the vent hole in your gas cap is literally sucking moisture out of the humid summer air and storing that moisture / water in your gas and that ' interaction' of water with fuel is turning into a crud inside the carb.
What did I do.
I talked to a guy who use to rustproof the bridges you drive over. He also invented the ' label less. - label' first used in Haines Underwear. It's that print in the cotton that will outlast the cotton itself. He's a creative guy. He has a product called CERMA FUEL TREATMENT. Why use this? It's a different kind of fueler stabilizer. He simply ' splits' the H2o or ( the water molecule) with his treatment. In other words the Hydrogen molecule no longer bonds with the O.....What we know the components in water or H2o is split apart and it's no longer ' water' or H2o. The Hydrogen becomes a very mild octane boost but nothing you will notice and the " O" just goes out your vent hole into the air. The water interaction which is the downfall of ethanol blended gas is halted. After 8 hours of heavy use, my Kohler 25hp stopped sputtering...backfiring and has been running smooth for 2 years straight. I got to my carb before the ethanol rotted it out. Dunno if you'll be that lucky. If not...when it get it . fixed and I suspect maybe a new carb might be down the road.....use this Cerma Fuel Treatment. I bought t

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