Carburetor

[Yeet 4]

Hello, I have a 1975 c120. I use it and every once and while the carb floods to the point where gas is shooting out of the air filter. It runs perfectly 90% of the time then this happens. I cleaned carb and tested float. It’s all good. Anyone know anything? Thanks. 

[ebinmaine 70,852]

Did you use an original Kohler rebuild kit? 

[Yeet 4]

I did not. I took it apart and cleaned every hole and tested the float. I then reassembled and it worked great for about 2 weeks.   

[wallfish 17,527]

A flooding condition is a problem at the float and or the float valve. (Unless there's an electric fuel pump pushing higher pressure)

I rarely change the valve seat and just change the valve. ( If cleaning the rubber tip on it and cleaning the seat doesn't work, which it does most of the time)

Is that an original carb a chinese knock off car

[Yeet 4]

Original carb and the float floats. Held it under water with weight for 24 hours and when I removed the weight on it it shot to the top. The carb is clean through and through. 

[wallfish 17,527]

10 minutes ago, Yeet said:

Original carb and the float floats. Held it under water with weight for 24 hours and when I removed the weight on it it shot to the top. The carb is clean through and through. 

Gas is different than water. Gas will seep right into a small hole whereas water can't due to surface tension of it. 

Wipe it off immediately after removing it and shake it. If you can hear/feel gas it has a hole but also look for a wet spot. The gas will creep out of the hole and you would see it.

Spraying isn't enough to clean the seat. A little carb cleaner and Q-tip works. Also CAREFULLY wiping the rubber tip on the valve. (It can twist off and break) 

[Yeet 4]

I took it off and shook it instantly when I did that test. I makes me think that where the little valve seals to the housing is bad. It is very clean. I mean clean clean. Somehow it’s bad? 

[wallfish 17,527]

7 minutes ago, Yeet said:

Somehow it’s bad

The little rubber tip wears. Try replacing that valve.

[Yeet 4]

I understand what you mean now….. why is that tip rubber….. when I cleaned it at first I didn’t notice. It’s <censored>ed.  Thank you man I had no idea. The 70s waz wildin.  Do you have a source for a part. I need the valve. Thank you so much. 

[ineedanother 1,461]

20 minutes ago, Yeet said:

why is that tip rubber….. 

It generally works very well, or it did until ethanol was introduced. New ones are more tolerant of ethanol but the original ones weren't. They come with a rebuild kit but are available individually but be sure to get the correct one. There are differences. Fuel inlet needle is what you're looking for.

[Achto 28,812]

2 hours ago, Yeet said:

I use it and every once and while the carb floods to the point where gas is shooting out of the air filter

 

I had this symptom on a Kohler carb once. On mine it turned out that the vent hole that runs from the bottom of the carb inside the bowl to the top of the carb inside the throat was plugged. With no place for the air to go when the float bowl was filling, it would force gas through the main jet into the throat of the carb.

 

This vent hole on the bottom.

 

Must have clear passage to this hole in the throat.

 

On a smaller carb the hole in the throat may be located here.

 

Here is a link for an OEM carb kit. (Part number 25-757-01-S ) They make aftermarket kits as well, but I don't recommend them. I will use a lot of aftermarket parts, but I will only use genuine Kohler carb kits.

 

https://www.amazon.com/Kohler-25-757-01-S-Equipment-Carburetor-Manufacturer/dp/B000P7P2HE/ref=sr_1_1?crid=3D2HKX492Q222&dib=eyJ2IjoiMSJ9.CGGfi7ox7IR8RsjmeMeqXuBo1nNSkVGuGyDjQ1UUtlEiSNKlPyisHPc6VctLEPSwcPn4bYTFNxZSgOu2yzgj9ks7jsGT2TrcVF9H9WOJBh22MI4Nw7rUPZwPE7atZHaw0SXcFWu7AeGC4RLyORU0zlkr0_acl3OpeZuqFl0NNlw_AKB-JP_ag0EKGwP1pQf638YF5Y0K0R57ek_8dzZq_Q2RLpS5x_bdfXKIgSHtaeQnuzpOjYPLW6C6PdPBU-ibI442MKqPOT153GBN0cOdD6qTeyF0eX-U9T_ORBnDaAw.A9FgWAezdLai5_obvQch3P8daOuIcZrn6JJe-_Mf_H8&dib_tag=se&keywords=kohler+part+25-757-01&qid=1745879942&sprefix=kohler+part+25-757-01%2Caps%2C180&sr=8-1

 

Note: You will require a thin wall 3/8" socket to remove the seat for the float needle. I just ground down one of my cheap deep well sockets.

 

 

Edited Monday at 10:50 PM by Achto

[Yeet 4]

My problem is that I sprayed carb cleaner through all holes and watched it go through.(including spraying myself in the eyes) I think it’s the rubber tipped valve thing. 

[Beap52 1,207]

In the "non tractor related discussion " under "what did you do today" on page "324" I discussed my flooding carburetor on a generator.  I used a Q-tip and polished the needle seat and flooding has stopped.  Apparently, there was ever so light build up of old gas residue that hindered the operation of the needle valve.  

[ineedanother 1,461]

1 hour ago, Yeet said:

My problem is that I sprayed carb cleaner through all holes and watched it go through.(including spraying myself in the eyes) I think it’s the rubber tipped valve thing. 

I "liked" your assessment above but will add that those who don't pull the welch plugs and put the body in an ultrasonic bath and then a good dose of compressed air are wasting their time and money.