Need help troubleshooting Kohler mower carb float needle valve


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Old 03-31-24, 09:13 PM
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Need help troubleshooting Kohler mower carb float needle valve

http://=youtube]eEtVYcgaprw


My latest carb for my old Toro mower for the Kohler xt-675 leaks out of the front at the choke plate. Needle valve looks feels new. Brass seat clean. So I'm testing both this one and the old one. Old one doesn't have top linkage that I think opens choke and it runs black and smokey so trying to get newer one working

To me it looks like both leaking and non-carbs hold air the same.

If there's nothing else it could possibly be I just need to either get another carb or a kit for this one which would be ideal but so far haven't found one. If anyone has a y ideas great otherwise I'll just throw on the older carb without th at top linkage and make a manuall choke switch somehow
 
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Old 04-01-24, 04:12 AM
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What did you use to set the float tang position? The web reference is not complete.
 
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Old 04-01-24, 05:25 AM
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beelzebob how do you set this position? And what do you mean by "web reference is incomplete"?
 
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Old 04-01-24, 05:27 AM
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Old 04-01-24, 06:22 AM
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While most carb manufacturers may spec a specific drill bit between the float and bowl rim on the carb body to set the needle seal point, a good rule of thumb is needle should seal when float is parallel to float rim on the carb body. Assuming the carb has correct float.
 
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Old 04-01-24, 06:27 AM
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beelzebob thanks.

I'm pretty sure it's close to parallel but I'll check again later. If it takes too long to seal, meaning it has to go higher than parallel, does that mean the fuel level will raise must that much and cause it to over flow though?

For me with the engine stopped it just flows with gravity as if the needle valve isn't even sealing.

Also might you happen to know how to adjust the seal point of these carbs?
 
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Old 04-01-24, 07:09 AM
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I have never really seen a needle and seat checked with a vacuum pump myself not really sure that's a good way of testing them. I would likely install a new needle and seat and think you may fix your issue some carbs actually have rubber seats not really sure what yours has but maybe cheese will be able to help you more.
 
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Old 04-01-24, 11:26 AM
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If the needle valve does not stop the gravity gas flow by the time the float bowl is full, the gas will run out of any openings between the float bowl and carb throat until gas tank is empty. Depending on the relative vertical position of intake valve and the bottom of the gas tank, it is possible to flood the intake manifold and gas gets into the engine oil in addition to running out of the air inlet. This will ruin any engine unless oil is drained and replaced. The part of the float that contacts the bottom of the needle valve is bent to adjust the seal position. I do this adjustment with the carb removed from engine. With the float bowl removed and the carb upside down and gas line attached to carb, I blow on the gas line to determine float location when needle valve seals and adjust tang accordingly.
 
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Old 04-02-24, 03:46 AM
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beelzebob

https://youtu.be/FnjFucVdC14?si=nnMz3obm-Ql--ZsE

How's it look?

As far as I can tell the needle valve and seat work right. So should I bend that little tab on the bowl the needle valve sits over down a bit then so it plugs the hole faster? I'm thinking it won't make a difference as if fuel is getting into up into the throat then it's not plugging the hole at all. Yet it seems to function.

Anyone familiar with this particular style needle valve and bowl for my Kohler xt675 carb? All the rebuilt kits are for the most popular needle valve with an actual spring which aren't compatible with my carb. They're the same carb just the needle valve is different



 
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Old 04-02-24, 10:04 AM
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If the needle tip is rubber, the seat is metal or if the needle tip is metal, the seat is rubber. Can you confirm you have the correct needle and seat? What engine info are you providing when you get the repair kit and from whom?
 
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Old 04-02-24, 11:14 AM
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Kohler PH-XT675-2070. I got my carbs off Amazon
​​
 
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Old 04-02-24, 11:15 AM
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beelzebob thanks yeah, the needle valve is rubber
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Old 04-02-24, 11:17 AM
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beelzebob im using a different carb now but it doesn't have choke control so I have to struggle with it. I'd prefer this one I'm working on but apparently it's a mystery how it's overflowing
 
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Old 04-02-24, 01:30 PM
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It would be the float, the needle valve, or the seat. It could be a combination, but most likely the float valve or the seat. If the float doesn't take on gasoline after being submerged in gas, its probable the float valve and seat not sealing. I would put a new valve in it and polish the seat up with a Q tip with a polishing compound on it. Then put it together and gravity feed gas to the carb inlet. The float should shut off the gas with light pressure on the float when it's about parallel to the the casting.
 
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Old 04-02-24, 01:41 PM
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If the carb was purchased on amazon, this is probably a cheap chinese knockoff. I would return it and try another or buy a OEM carb.
 
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Old 04-03-24, 06:50 AM
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cheese where do you get your carbs? Or rebuild kits. I'd like to get a few gaskets, and valves, and a jet I destroyed
 
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Old 04-03-24, 11:48 AM
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It depends, I get different cabs from different places, shopping through the usual parts suppliers and also ebay sometimes for the best deals. Or sometimes straight from the manufacturer.
 
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Old 04-05-24, 09:26 AM
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Chuck, I think someone told me a long time ago, that you are not supposed to use a sealer on float bowl gaskets. I occasionally have to lift my golf cart up from the front end, which causes the gasoline in the Zenith Carb to rise above a point where the bowl gasket (it is a very large disc type gasket that covers the entire diameter of the float bowl over the top of it) meets the outside diameter of the float bowl, and the round bottom of the carburetor. ) I had had enough of gasoline pouring our of the back of the carb and onto the floor, so I sealed the gasket, carb bottom, and the rim of the float bowl with some locktite black RTV MAX and put it back together. Problem solved. Engine runs great. (Borrowed Time?) The sealer is only on the rims of the mating surfaces and the rim of the large gasket, NOT the whole gasket area.
 
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Old 04-05-24, 09:48 AM
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most all of the silicone gasket sealers are not gas resistant so it may not last really very long.
 
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Old 04-05-24, 12:34 PM
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That begs the question then. What sealer CAN be used in an application involving gasoline, like carbs and fuel strainers? I have both holding together (and keeping dry for the moment) With the loctite.....
 
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Old 04-06-24, 07:37 AM
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not sure I would use a sealer on a carb or fuel strainer best would be to source a gasket or make one, of the sealers that are gas resistant there is some like permatex, motoseal or aviation or hightack are all gas resistant sealers some of the loctite anaerobic adhesive would also be gas resistant but likely not a good choice for something you may want to remove in the future but you need to follow the cure time recommendations for about all of them for them to work.
 
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