Onan Genset 4.0 Fuel Pouring onto Choke Flap

[koobs2000]

Hello,

I have a 4.0 that has always run fantastic. Just now if has a problem starting/staying running. Its doing something unusual. Gasoline is spitting up on top of the Choke flap and out the sides of the air intake plastic thru a small hole at the top of the carb. When the 4.0 is running good if you look down the carburetor you can see the fuel at the bottom of the carb right before it enters the cylinders. Im wondering if my floats are stuck and this is the overflow process or if there is another reason. Any help would be greatly appreciated. I have attached 2 pictures. One of the generator itself and the other is of the top of the carburetor. Looking at the carb u can see the small hole on the right hand side. That is where the fuel is coming out of!!

Thanks,

Jakub

 

[ChasA]

Yep. Stuck float. May have a hole in it. Especially if it's a metal float.

 

[Matt_C]

Jalob,
Chas is correct, it is a fuel level control issue. It is most likely a simple thing. If you take it to a Cummins/Onan shop, they will probably try to sell you a complete carburetor. Find a friendly small engine shop, or dismantle it your self on news paper in some place clean.
Matt_C

 

[koobs2000]

Thanks guys!!

I was hoping someone would confirm my suspicion about the floats. This happened b4 and when i removed it from the motorhome and set it in the garage the float corrected itself because it ran great.
The floats are metal. I will take it apart and check for holes!!

Thanks for all your help!!

Jakub

 

[DonTom]

I was hoping someone would confirm my suspicion about the floats. This happened b4 and when i removed it from the motorhome and set it in the garage the float corrected itself because it ran great.
The floats are metal. I will take it apart and check for holes!!

Thanks for all your help!!

I recently replaced my carburetor in my Onan 4k Generator 4.0 KY-FA/26100 J generator with a cheap $40.00 from Amazon. It works perfectly in my generator. I just gave it a 5 star review on Amazon.

-Don- Auburn, CA

 

[koobs2000]

Thanks for the heads up Don but that carb will not fit my Genset!! Way different model!

 

[John From Detroit]

One word of caution.. Had a Dodge van that keept doing that, Crud in the needle valve (The valve the float floats)_ turned out the fuel pump Diaphragm was flaking away and shortly after failed.

 

[Gary RV_Wizard]

If not the KYFA 4.0 Onan, what model do you have? The old BFA? Amazon and Ebay typically have Onan carbs at reasonable prices.

 

[Ex-Calif]

Sunk float or needle valve and seat or just a bit of dirt in the float bowl fouling the needle and seat.

I'd pull the top off the carb float bowl before I started ordering parts.

 

[skydivemark]

Thanks guys!!

I was hoping someone would confirm my suspicion about the floats. This happened b4 and when i removed it from the motorhome and set it in the garage the float corrected itself because it ran great.
The floats are metal. I will take it apart and check for holes!!

Thanks for all your help!!

Jakub

Some years ago I had a similar problem with a couple pin holes in a metal float. I soldered the holes closed and it worked great.

 

[koobs2000]

Gary,

Its a BFA. Not sure what year though!!

Everyone else,

Thanks for all the help!! Im glad we all agree on what the issue is!! Floats!!!!! I will take it apart and take a look!!!

I will let you know what i find!!!

Jakub

 

[DonTom]

Gary,

Its a BFA. Not sure what year though!!

Everyone else,

Thanks for all the help!! Im glad we all agree on what the issue is!! Floats!!!!! I will take it apart and take a look!!!

I will let you know what i find!!!

Jakub

Thanks for the heads up Don but that carb will not fit my Genset!! Way different model!

They also sell the BFA carbs.

-Don- Auburn, CA