Carter YF Carb Help

Friend took carburetor apart to clean it. It was rather dirty. When he did, he lost one of the small balls that sits in the bottom of the carb. I'm completely carburetor illiterate.

Now, when we try to crank it, fuel floods all out of the carburetor. Is this a result of the missing ball or has he reassembled something else wrong?

It's a 75 CJ5 with the 232 and Carter YF 6424.

Help. Now my Jeep doesn't run.

 

Well, a missing check ball is not a good thing. Without knowing which one it is hard to say if that is causing the issue, but if you reassembled it without the ball, then a good chance that is the problem. Time for a rebuild kit.
Also check and make sure there is not debris in the needle valve and seat. That will also cause it to flood as you describe.

 

Again, I'm carb illiterate. I believe it was near the bottom of the carb under some rubber grommet. It looks like some sort of drain.

We reassembled it with one ball. We dropped the other one.

Whats a good source for a rebuild kit? Thanks for the help.

 

There are some online carb kit suppliers but I go to my local Napa store. I like supporting the local guy if possible and if there is a problem easier to deal with a person face to face. I've found the Napa kits (Echlin if I remember correctly) to be very good.
Hopefully someone will chime in with the online suppliers of the quality kits as the names escape me right now. Might also try a search as well.

 

Thanks. I appreciate it. I will try to find a rebuild kit. I need to find a good source for a manual or something because I have no idea what I'm looking at with this carb. I don't want to just give up and take it somewhere because I'd like to learn. Just need to figure out where to begin.

 

The TSM (Technical Service Manual) or FSM (Factory Service Manual) is a good place to start. Resources on where to purchase have been listed a bunch of times. If you can't find the info with a search contact member Timgr. I believe he posted the info several times and may be able to help.
That manual is the single best purchase you can make as a Jeep owner who wants to learn how to work on it. Stay away from the Haynes and Chiltons manuals.


Sent from my iPhone

 

The 1975 factory manual (TSM, FSM) is available many places as a reprint. Here's one: http://www.bjsoffroad.com/prod-670.htm - Here's another - http://thejeep.com/shop/TECH+MANUAL....html?osCsid=385b7903fcd57ce8400b00651015ed89 All of the Jeep specialty retailers will have it.

The original manual is for sale on Amazon - http://www.amazon.com/Jeep-Wrangler...8-2&keywords=jeep+1975+factory+service+manual - I hear they also show up on eBay quite often.

You can also look at the 1974 or 1976 manuals here http://oljeep.com/edge_parts_man.html - chapter 4 covers the YF. There will be differences - some major, some minor - between these manuals and the correct 1975 manual, but the section on the YF in Chapter 4 will be mostly the same.

As fair warning, almost everything changes for the 1976 model year CJs. There are very few parts of the 1976 manual that will be helpful for your Jeep.

Take a look and see if this is accessible to you. The TSM is written for dealership mechanics, but most readers can understand it.

 

I consider myself a fairly decent mechanic. Just never messed with anything this old.

Appreciate the help guys. Going to take a look at the info provided as well as some "carburetor theory" and see if I can't figure out what's going on.

 

Finally had a chance to look at this today. I'm wondering how much play there should be in the accelerator pump as it moves up and down. Mine seems to be really sloppy and it binds up a bit. Not sure that's the problem, but it was something I noticed.

I also seem to be missing some parts. The weight and check ball for the discharge pump seem to be totally gone and the inlet ball and retainer are also gone. That seems to me like it could be related.

Another question: is the small rod that is attached to the accelerator pump the metering rod? If so, is it supposed to ride on top of that inlet check ball? That was the way I interpreted the diagram.

Anyone want to confirm for me if I'm at least in the ball park? Hoping to pick up a rebuild kit this week.

Edit: Answered at least one of my questions (about the metering rod) although based on the diagram mine may be wrong:

 

Looking like it was the metering rod arm being way out of adjustment the whole time. It's running, but not idling..trying to figure that out now.

 

If you turn the idle mixture screw in all the way, the engine should stall. With the idle mixture screw turned out, say 3 turns, If the engine does not run at idle speeds, then you have something plugged up in the idle circuit, or parts missing. I'm guessing the latter.

I suspect you will need the discharge weight and discharge check ball in place for the idle circuit to draw fuel at idle. Go back to where you were working and find these parts. Look at the diagram in the TSM. It looks like these drop into the passage in the top of the carb, and are held in there by the carb top. There is nothing under the metering rod - it moves up and down in the jet to richen the mixture under the effect of vacuum and the lifter link. This is shown in the YF carburetor section starting at page 4-8, in the '76 manual that I linked to above. Adjustment of the lifter link to set the metering rod height will have a big effect on operation.

Inlet ball? There is no other ball AFAIK. There is a needle that is part of the float assembly. This keeps the fuel at a fixed level in the float bowl. The carburetor will not work at all without those - without them, you will have gas spurting out of the top of the carburetor, stalling the engine (if you are lucky).

All the parts are named in the TSM. It will be helpful to use those names to describe the parts you are referring to. Look at the exploded diagram.

 

Thanks, Tim.

We got it running pretty good last night. For some reason when we adjusted the metering rod it wouldn't idle. A quick adjustment of the idle mixture screw seemed to clear that up.

I still think I am missing a few parts from where the PO did a rebuild. I will likely still purchase a rebuild kit and rebuilt it since I'm pretty familiar with it now.

Thanks for all the help guys. Just glad it's back running. Definitely did not want to miss the next few weeks here in NC..the weather will be the nicest it is all year.

Edit: It's probably worth mentioning that we ended up adjusting the metering rod by following a YF video from "Mike's Carburetor" on YouTube. Pushed the pump all the way down, adjusted the rod that way. As soon as we tried firing it back up, it ran fine..just wouldn't idle. We turned the screw in about a half turn and it fired right up and idled perfectly (better than before this fiasco, ironically).

The "ball" I thought I saw was just fluid that the light hit exactly right and looked like a reflection off of the top of that silver ball. Once I got a solid diagram I was able to tell that it was a jet..not something that would be plugged up by a ball.

As I said before..was very carb illiterate before messing with this. I still am, but I have certainly gained a bit of knowledge with this experience.

 

As far as that check ball goes, mine wouldn't reseat consistently on my YF. After hitting the throttle (which in turn engaged the accel pump) the carb would dribble gas down the throat. Eventually it would die from going way too rich at idle unless I rev'ed it to clear out that excess fuel.

With the top off the carb, after pressing the pump, I could see loads of gas coming out of that orifice when it wasn't seating right. It should seal up tight so even small throttle hits don't essentially empty the entire pump shot.

I ended up tapping mine lightly with a screwdriver handle against a drift to "reform" the ball seat and then it was fine.

I can't imagine its going to work well *at all* without that check ball in place. Even "kinda working" in my case was very troublesome.

My kit didn't come with a new check ball, so make sure you find one that does.

 

I just bought this kit. It's still not running as well as it was. It's running decently, but it's inconsistent. It will run fine around 55-60 and then just die, backfire extremely loud if I rev it up, and carry on. I think I fixed the backfire by tightening the carb down to the throttle body, but I haven't been able to fix the random miss while driving. It idles great, though.

Hoping the rebuild will fix it. From what I've been reading, though, the YFs are pretty temperamental and difficult to get exactly right.

 

You mean tightening to the manifold? There's no throttle body on a carbureted engine.

This indicates that you have vacuum leaks - vacuum leaks are bad, because a carburetor uses vacuum both as a signal and as a power source for the metering circuits. One thing the rebuild kit gives you is new gaskets so that vacuum leaks likely go away. Be careful of overtightening - it is possible to crack the carb body, esp. if you aren't sitting perfectly flat on the gasket. But it's hard to say if you are still missing parts.

The idle circuit is completely separate from the running circuits, and its mixture is adjusted by the idle mixture screw. Not much to go wrong. Once you come off idle, things get more complicated because you have to adjust for the manifold vacuum changes due to the throttle plate opening, and the demands of the engine wrt to load, speed, and change of speed.

Mmm. No extensive experience with the YF, but it was used on a lot of cars for many years and seems to be pretty trouble free. The metering rod is a clever and sophisticated way of changing the mixture, and works very very well when it's adjusted right. I would be optimistic about it - carburetors do wear out, but the YF has a pretty good reputation, I think.

I recall something about a lifter link seal in old posts. The F134 guys discussed it. Supposedly gas will seep down the lifter link without it, and the cheap kits do not include it. That's my only critique of the kit you linked too - looks fine otherwise. That kit supposedly contains your missing parts, so that's a step in the right direction certainly.

 

"he lost one of the small balls that sits in the bottom of the carb."
If it helps at all, about a million other people have done that, turning the carb upside down.


YF has never been at all finicky to me. Just the opposite. I have ladled the crud out of them with a spoon, and they ran great afterward.

Fuel flooding out is usually a simple float or float-valve problem. Be aware of the getting correct float valve for Jeep applications, and setting the float height accordingly. They differ. Not all kits have the right one. (Search the archive here for details.)

The throttle shaft bearing areas can leak air if badly worn. Another thing is to check that the carb base is flat... over-tightening can bend the flange ears and the gasket will vacuum-leak.

Although the above are usually idle issues.

 

Well good to hear. A lot of the forum posts I've read have said that they could never get the YF to run exactly right, etc.

I figured losing the ball happened to others..as mine was missing one of them completely.

The flooding seems to be resolved for now. The carb base was loose but I was able to tighten it down enough to resolve the backfire issue from what I can tell. At this point it just has a really minor miss occasionally.

One of the other questions I have (and this is probably addressed in the TSM) is what vacuum connections I'm supposed to have on that carb. When I got it the only hose running to it was the fuel hose..so pretty much no other vacuum connections. There are various vacuum connections that are unplugged and plugged with screws and such under the hood. Anyone have a good reference for vacuum routing on the 232?

I would like to pick up the TSM eventually, but 75 bucks is more than I can do at the moment.

 

Re vacuum routing, look at the '74 and '76 manuals at www.oljeep.com (linked above). There is no "vacuum diagram" as such - instead each emissions system component is described with its connections shown. Both these manuals will be pretty close to what you have, though not exactly the same. Emissions devices were changing a lot from year to year around 1975, but you should be able to figure out what changes.

There should be a orifice-restricted vacuum connection for the choke (to a source of hot air in the exhaust manifold, the "choke stove"), and all the other connections on the carburetor will be ported vacuum. It's hard to describe what you need to have without a lengthy discussion of emissions devices. Suffice to say, you need vacuum advance for the engine to run at all, and any port that is not connected to something and is pulling vacuum should be connected or capped. Otherwise look at what you have, consult the manuals, and make a plan.

What exactly is the configuration of this Jeep? California or 49 states? 232? A '75 232 CJ-5 has internal engine mods (distributor, cam, carb), fuel vapor recovery, PCV, spark CTO, TAC and TCS. A California Jeep adds EGR. You are lucky - this is a very short list, compared to other models. Simple. This is so basic, I would certainly keep all of it. All of this stuff is defined in chapters 4 and 4A of the linked manuals.

 

Thanks, Tim. It's a non-California 232.