carb overflowing

have a problem , maybe someone has incountered . have a f134 with factory carb carter . bought jeep with 2 carbs , a overseas carb and original carb . could never get china carb to ever run right , but looked new . so i thought i would try the old one i had in a box , took it apart looked re built . put it on the jeep, it runs amazing , more pep , it purs ! . BUT when riding along a trail and its rough , it will stall and gas pours out of the bottom , wait a minute bang a little on the carb cranks back up perfect ... till it does it again . more fequent now . so i remove top of carb and i suspect it is the ruuber neddle valve on float sticking ? check this and clean , no dirt or burrs on needle ? but do notice the male needle will bind when manipulating the float . so i polished the needle so it would be smooth in seat . still binds ? also noticed the female side that the needle has a ton of play so it appears the needle is getting side ways and actually binding , so when bowl gets low the pin drops out and gets wedge between side wall . tap carb and frees it for a moment till it happens again ? is the needle supose to have that much play ? i have done other carbs and seems this one is really loose fitting . hate to screw to much with it because its running so good .is there a kit availiable that has these 2 items [ needle and seat ]? thanks for taking the time to read all this

 

kit should have needle and seat included

 

if you can find a GOOD PARTS MAN you can buy just the needle and seat. i ran into something like this several years ago on a big block chevy. the neopreme tip kept coming apart. and that is what come in the kit. he got me a needle and seat without the neopreme tip

 

Sounds like you may have a parts mismatched fuel valve. I can help with your fuel valve ( needle and seat ) questions, When I get home from work tonight I will post up the correct Napa part number for a proper kit and a part number for just the neddle and seat for the Carter 938YF and some other information about the fuel valves for these you should know and may find useful.

 

thanks brian , i think i have two differant parts too . i dont mind buying the whole kit if the two parts are not avaliable . can allways keep it for spare .

 

First a little history on your fuel valve ( needle and seat ), The original fuel valves came with a spring loaded steel needle, the orfice diameter in the seat was .076 inch. these fuel valves are still available from many jeep parts suppliers.

Carb kits from many parts houses can contain a number of parts you dont need as well as some that can be slightly off specification because the kits are designed to cover a very broad range of carbs in a specific family. Even carb kits from specialty suppliers can at times contain off specification parts. This has contributed to many a good carb being put on the shelf.

When replacing the fuel valve you want to stay as close to the original .076 seat orfice as possible if you dont have an original specification valve. The reason for this is that too large an orfice will allow the fuel pump to overpower the float and flood the float bowl.

There are two common fuel valves that you usually get in a generic kit thats not from a reputable 4wheel specialty supplier . They are usually both rubber tipped and in separate packages within the kit, One will be spring loaded with a valve seat orfice of about.084 and the other will be a solid needle with a seat orfice of about .096. The .096 seat will result in flooding.

The rubber tipped spring loaded fuel valve with the .084 seat orfice will usually give good results running a stock mechanical fuel pump that puts ot 2.75 to 3 psi, Pressure higher than this will likely cause flooding and would require a fuel pressure regulator.

I have had good luck with the spring loaded fuel valve that comes in the NAPA kit #2-5096, I run this valve in my 938YF with good results. For the spring loaded fuel valve only ask for part #2-3724, for the pump diaphragm only ask for part #2-4218.

Depending on how bad its acting you could order some original spec valves ( I recommend keeping a spare fuel valve and pump diaphragm if budget allows ) and wait for them.

From your discription above I think your existing valve itself could be a parts mismatch between needle and seat. I would try just replacing the fuel valve and see how it goes.

I have noticed that the parts dimensions have changed some in the last few years, The valve as an assembly may be a little to long. The spring loaded fuel valve in the NAPA kit may need to have the valve body, needle and pin shortened about .040 to .050 or so to prevent excessive bending of the float arm tab to adjust the float. This may be more a matter of preference but I prefer not to flatten or excessively bend the float arm tab.

If you have any more questions I will do my best to help you with them.

 

thanks again brian ,is the pump diaphram the fuel pump diaphram or is there one in the carb ? and thanks again so much

 

The pump diaphragm I am referring to is the one in the carb, Its the accelerator pump diaphragm. This part does dual duty in the YF by also utilizing manifold pressure (vacuum) as part of the system to control metering rod position.

If after you replace the fuel valve the needle still tries to lodge itself behind the little float arm when the float is set for the proper amount of drop the slight arch/radius in the float arm may need to be carefully reformed. It could have been flattened or pushed toward the float by someone trying to use needle nose pliers to adjust the float level, Its easy to squeeze the slight arch out of this arm/tab while adjusting it if ones not careful.

 

hey brian p , just got my part fron napa , i am kinda confused maybe you can help . i ordered part number 23724 . in the napa picture it shows a needle and seat with a bent wire retainer spring . when i received my package from napa it came with a needle that has a little coil spring that goes in the needle with a pin that goes inside the needle . is this the one you thought it was ? or do i need to go and ask napa if the item numbers may of gotten screwed up . the number on the package the seat came in does not match the box ? , i dont want to try it if it isnt the right one . thanks

 

If you ordered the 2-3724 part and got the one with the little spring and pin you should have the right one. Dont worry about what the picture in the catalog looked like as its representative of the family of parts not the specific part in all cases. The early YF does not use a bent wire retainer.
Go back and read the last sentence in post #6, If you think you may have trouble adjusting the float arm to fit the new fuel valve let me know.