Kohler carb running lean

johnorlandi

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Hi guys first time at this site, used the B&S forum and it was helpful

I have an Acgo Allis garden tractor with Kohler CH18 s and the carb has been replaced with a keihin 24-053-35.

I believe it is running lean

It back fires threw the exhaust only under heavy load, other than that it runs smooth

There is no viseable screws for adjustments . The only thing is a selonid with 12 volts going to it

I have not tried running with the choke out a little for it only happens under heavy load

how do I adjust the carb

Thanks

John
 

7394

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What do the spark plugs read (look) like ?

Backfire from exhaust is more likely from too rich condition. Thru the carb would be too lean. Again, the spark plugs will tell you how it's burning.
 

Darryl G

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Could be water-contaminated fuel causing it to backfire too.
 

johnorlandi

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7394 and Darryl

The plugs are tan in color so burring lean

The fuel was just bought so I think it is water free but I did add a bottle of dry gas just in case

Any idea on how to richen up the carb?

Thanks

John
 

Darryl G

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But is there water in the fuel system? I'd drain the fuel bowl if it's equipped with a drain and check for water, if not pull the bowl and check. If there's water in your fuel system you'll likely find some there.

Don't know how or if you can adjust your carb. Still not convinced you're running lean. Like 7394 mentioned, backfiring out the exhaust is usually indicative of a rich, not lean condition. And light tan/brown/grey are usually indicative of normal engine operation. I actually buy my plugs from my mechanic/Husqvarna dealer and hand him my old plugs when I do for him to inspect.
 

EngineMan

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Tan is the right color for normal condition, you can't adjust that carb, so if its not water in the fuel I would be looking at the valves next.
 

johnorlandi

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I will drain the tank this weekend

There is no bowl on the carb

Then we can go from there

Happy Easter to all

John
 

bertsmobile1

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I will drain the tank this weekend

There is no bowl on the carb

Then we can go from there

Happy Easter to all

John

OooH are you in for a surprise.
Your carb has got a float owl and it is the child of an unwed couple to work on.
Take the full numbers off your engine and get an exploded parts diagram.
The carb is a downdraught concentric bowl carb ( bowl goes around the outside of the throat )

Kohler workshop manuals are available from Kohler as a free download ( no excuses , abduct a 12 y/o if you have to )
 

johnorlandi

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Bertsmobile1
What was I thinking that I did not have a fuel bowl. All carbs need a fuel bowl to operate for the flow, excuse the ignorance.

drained the fuel tank and took the top off the carb look inside the FUEL BOWL, no water, with plugs the right color no water what do I do next any ideas?

Engine Man mentioned the valves, are you talking adjustment of the valves that has never been done on this engine and I have maybe 900 to a 1000 hours on it.

Ran reel great until the carb gave out, replaced with a new not rebuilt and different trouble. Maybe I should have rebuilt the old carb

I have another brand new Keihin carb # 24-053-32 but that is for a different model Kohler engine that I might try if I can not fix this one

HAPPY EASTER ALL
John
 

EngineMan

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If the problem only came after the new carb, then if you still have the old one then rebuilt it and try and if the problem goes away...!
 
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