# Kohler CV730-0017 Sputtering



## mikeinri (Dec 2, 2009)

Hi guys,
New problem. 25HP Kohler engine on my GT5000 Sears tractor. Stalled while snow blowing, probably ran out of gas (was low when I started).
Filled the gas, now it won't run smoothly (full throttle) without a little choke. The engine surges with no choke. Runs fine with no choke under load (snow blower pushing snow).
Fuel filter, air filter, oil and plugs were new in December, and it's been running great up to now.
So, what's going on? If it got sediment from the low fuel, shouldn't the filter have stopped it? I doubt it's the pump, because it's too coincidental. I was planning to rebuild the carb in the spring just due to age (2003 unit I just bought used in Nov).
Ideas?
Mike


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## jrrdw (Jun 26, 2010)

Try draining the carburator bowl, remove the solenoid on the bottom. Careful these solenoids are kinda fragile, make sure you have a thin enough open end wrench to fit in between the bowl and outer casing of the solenoid. 

Hold the carburator bowl on the carburator by hand so it doesn't fall off. Now get help to turn the engine over so clean fuel will flow through and flush all the condensation and any debris out. 

If that doesn't work you can try adjusting the fuel air mixture needle, if that still doesn't work you will need to clean the carburator. The jets are probably clogged.


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## mikeinri (Dec 2, 2009)

Thanks.

Just to make sure I really understand this...

I have a service manual, and this appears to be a Nikki carb (part number is 24-853-90-S per the Sears and Kohler websites' parts lookups). 

EDIT: I also found this page, which is somewhat helpful but doesn't show the solenoid in place:
Disassembly of Kohler Command V-twin Nikki Carburetor

You're saying to remove the solenoid, which appears to hold the bowl in place, correct? 

When the solenoid comes out, the fuel will flow right out of the hole where the solenoid resides, correct?

When I'm holding the bowl and the engine is turning, how much gas should come out at me?

I'm not seeing where I would need a thin wrench by the pics I'm looking at, hopefully it will make sense when I have the engine in front of me.

Still not sure how anything got by the new fuel filter, that bugs me.

Mike


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## mikeinri (Dec 2, 2009)

And why does it run OK while under load?

Here are the symptoms again (warm engine):

Fast throttle, no choke, no load: surges

Fast throttle, a little choke, no load: runs OK

Fast throttle, no choke, with load (snow blowing): runs OK

Fast throttle, a little choke, with load (snow blowing): wants to stall (obviously too much choke)

Mike


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## K-B (Oct 24, 2005)

Sometimes if the carburetor has a partially closed passage it will run fine under load but surge when not under load (exactly what you're describing). I agree with jrrdw, it does sound like a carb problem. 

For that particular carb/solenoid, you don't need the thin wrench. And yes, once you remove the solenoid fuel will drain out that hole. When you're turning the engine over with the solenoid out, fuel should flow out at a steady, relatively fast rate. It won't spray out with pressure, just a nice flow. If it doesn't flow and just drips or doesn't do anything, that would indicate a problem with the fuel pump (if equipped).

Fuel filters don't keep all foreign materials from entering the carb. If they did, there would be no problems with carburetors getting dirty


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## mikeinri (Dec 2, 2009)

Ha! Makes sense, thanks. As I said, I was planning to rebuild anyway, now I have a "real" need.
Mike


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## mikeinri (Dec 2, 2009)

Hey guys, the snow stopped so I'm getting ready to deal with this. Any chance running SeaFoam through it would clean it enough (without having to do a rebuild)? 

I really hate to rip apart a carb that was working perfectly until it sucked in some garbage...

Mike


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## K-B (Oct 24, 2005)

It would be worth a try, I've never used Seafoam but I've heard good things about it.


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## bozodog (Nov 27, 2009)

mikeinri said:


> Hey guys, the snow stopped so I'm getting ready to deal with this. Any chance running SeaFoam through it would clean it enough (without having to do a rebuild)?
> 
> I really hate to rip apart a carb that was working perfectly until it sucked in some garbage...
> 
> Mike


Yes, use it at twice the recommended amount for a tankful.


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## jrrdw (Jun 26, 2010)

Here's another way carburators get dirty/clogged. Temperature change! Cold, warm, cold, warm causes condensation to form water bubbles in the bowl. The water bubble causes a small separation in between the water and gas, then that itty bitty air bubble causes oxidation witch in turn clogs up the jets in your carburator! 

That's today's science lesson boys and girls. :laugh:


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## mikeinri (Dec 2, 2009)

I hear you.

In this case, it was a pretty obvious cause and effect. I ran it out of gas, and the problem only showed up when I restarted. Most likely injested something from the bottom of the gas tank.

I'm generally pretty skeptical of magic potions, so I'm planning to have to rebuild the carb. However, I don't want to rule out a chance to get lucky!

Mike


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