Carburetor Leakage at Throttle Plate Shaft Ends...

Gents,

I noticed the other day, after having started my '62 CJ-5 F-134 to let it run and turn the wheels (while it sits on the jackstands, and I await my brake lines that are on back order and 30 days out)that when the engine is shut down, I can see a very small amount of fuel leaking out where the throttle valve shaft penetrates the carburetor body on both sides. It only does this for a short while after the engine is shut down and then stops. I am trying to understand why this is happening, as I have never seen it before.

The other side of this coin is that I would assume that when the engine is running, there is air being sucked into this area. I can completely close the mixture needle valve and the jeep will run smoothly. However, I can back it out and I will eventually reach a point where it runs quite roughly and appears to be running rich as I would expect. I would also expect that I shouldn't be able to shut that needle valve completely closed and have the Jeep still run smoothly.

What was the OEM carburetor for the '62 F-134? I can't seem to find anything on the body of the installed carb that indicates what it is. It looks a lot like a Solex (having worked on many a VW), but I can't say for sure.

Has anyone tried to put the 2-barrel Holley carb that was used on the 2.3 liter Vega engine, on an F-134? I modified a manifold on a VW engine in a Karmann Ghia and installed one after I took the engine displacement out to 2300 cc or better, and it was a great carb. It had mechanical secondaries and worked nicely throughout the whole power range with no flat spots eve when the secondaries opened. Speaking of which, it appears that the accelerator pump on this carb is stuck the actuator rod moves and the spring compresses, but the diaphragm operator lever doesn't move.

Anyhow, I would like to replace the carb on the F-134 engine and wonder who has had what experience with aftermarket carbs. Any and all recommendations accepted. And, if you all have any ideas on the carb I currently have, pass them along, too. The original owner told me that he has had issues in hill climbs where the carb seems to either load up or lean out (he wasn't sure which way it was happening), both going up the hill and then coming down. I don't plan on driving on level ground very much, so pass along any ideas/experiences you have had. I would like a good carb for the engine as it seems to be fine after my rebuild. No leaks, no smoke and it sounds like a MASH jeep. There is no other engine in the world that sounds like that.

Thanks...

 

The choke plate is not at the top of the carb. That is why I thought it might be a Solex. Hey, I just found a picture of it and it is a SOLEX. Any recommendations for it? Junk it? I know they were a troublesome carb in the VW's, especially with the cut-out solenoid, and crappy idling circuits. Let me know what you all know...

Thanks...

 

Get a carb kit and a new throttle shaft from The Carburetor Shop. Fixed my similar problems. About $100 in parts.

 

Go 1V Rochester TBI from a 151 cid Chevy.

Here's an example to think about - http://www.binderplanet.com/forums/...way-to-fuel-inject-a-4-cyl.48571/#post-285660

It would be easy to go fuel-only with a Megasquirt 1 - http://www.diyautotune.com/catalog/...le-efi-system-pcb30-kit-black-case-p-108.html - the main things you'd need are the throttle body, the MS 1 board, and some kind of manifold adapter. It's pretty easy to make your own adapter from a small aluminum plate, a drill press and a die grinder.

 

Hi Glenn......any idea where you can get the bushings for the YF throttle shaft? I have had to rebush a SU carb once and it made all the difference in the world with the air/fuel mixture. I have not even looked yet to see if there are replaceable bronze or brass bushings in the YF but eventually it always becomes an issue on these older carbs.

 

I got lucky and just the shaft took care of things, but it may not in your case. I also went thru the run of the mill suppliers for a carb kit, and although the parts fit, they are incorrect. The above supplier cured all my carb issues.

 

The (YF) carb needs to be bored for bushings, and requires a precision tool to do that. I found it cheaper to just buy a NOS YF on ebay.

In general I never found the YF to be fussy.

 

Thanks to all of you for the information and the links. I will see how this carb works once I cure the ills, but if I do find a 2-barrel Holley, like the one I had I will figure out a way to get it on the manifold, even if I have to build a box in the hood to make it fit. I think it would be an ideal carb for this engine.

You all have a nice, "rest of the weekend", and thanks again.

c.

 

I have not owned one, but that carburetor is a popular upgrade for 258s that came with the Carter BBD 2V (the carburetor that everyone loves to hate). The 32/36 DGV is a progressive carburetor, with a 32 mm diameter primary and 36 mm secondary. I expect it will work fine on the 134, but I wonder if you'd ever make good use of the secondaries. I'd expect the downstream plumbing to be very much more restrictive than the carburetor. But Redline sells it adapted to 1V manifolds, ie the 134 and 1V 232s and 258s, and there's no reason why it would not function fine - but not up to its full capacity.

The Webers are said to be very sensitive to fuel pressure, so a fuel pressure regulator is often used with them.

I think your selection of junkyard carburetors is pretty limited today - there just aren't that many carbureted cars in the wrecking yards anymore. If you must have a new carburetor, your options are also limited - the Solex, or this Weber. You could also consider the Stromberg 97, which is sold for the retro hot rod market http://www.stromberg-97.com/carburetion/stromberg97.asp#prodfrm - not a cost effective choice, I would think.

 

I am very interested in this. The only thing I wonder about is the height. I managed to make my own slimline air cleaner to sit on top of the current carb and still close the hood with no interference. If this is close to the same height, I could do it again. I did find the Holley 2-bbl carb I used in the past, but making a conversion with limited room might be an issue.
Thanks for the help. At least now I have some options...

Later...

 

I just want to make sure I don't do something stupid like "over-carb" the engine. I have seen too many guys who had the idea that if a 650 cfm carb was good, then a 1000 cfm carb must be just that much better. I wish I had ten dollars for every guy I knew, when I was growing up, who had no idea what they were doing when it came to carbs. I had a '67 GTO with a Firebird engine in it (blew up the original 400) and I had it dialed in. It had the Ram Air IV option on it, and I had made it fully operative in the GTO, but I think it was more a sales gimmick than anything. But I wish I could find the formula I used in determining the right size carb for the engine. It would kick butt on everything else in town. I am sure you probably know the formula off the cuff of your sleeve, Tim. It wasn't that complicated. Thanks for the info you gave me. It is appreciated...

 

Pretty easy to calculate the CFM at a given RPM and displacement. Use dimensional analysis.

134 in^3 volume
2 revolutions/volume
4000 revolutions/minute
1 foot / 12 inches

Now put what you know together so that the dimensions give the result that you want - CFM, or feet^3/minutes

134 in^3 / volume * 1 volume / 2 revolutions * 4000 revolutions / minute * [1 foot / 12 inches]^3 = 155 CFM.

This assumes 100% volumetric efficiency, that is, that the intake path is so smooth and large that the cylinder fills completely. We know this isn't true, but we can conclude that you should not need more than 155 CFM to get everything out of the F134 that is possible without forced induction. The Stromberg that I linked to is 162 CFM, and the hot rodders would use maybe three of them on a flathead V8.

The main tradeoff you are worrying about is power versus control. You need some vacuum to control the fuel. If you use a too-big carburetor, the hole is really big for the voulme the engine is pumping, and control goes away. Generally speaking, a smaller carburetor gives you better control (more vacuum which you can use to meter fuel) and less power (more restrictive intake means that the cylinder does not fill completely - there is some residual vacuum in the cylinder).

From this simple calculation, I'd guess that you need something in the range of 100-150 CFM. I think you would be ok with the Weber, since the primary venturi is pretty small (32 mm, or 1.25"). The 36 mm venturi is a secondary, and will only open if there is enough demand. I expect this is a vacuum secondary (ie only opening when throttle position and low vacuum demand more flow), but I'm not certain about that.

My feeling is that the 32/36 DGV will work with the F134, but I wonder if the secondary will ever open. If not, you may as well run a Carter YF, or a Solex, or a Holley 1940, or some other 1V carburetor. If it were for me, I'd try and fix the YF. I ran a YF on my '75 CJ-6 with a 258 for many years, and it was fine. If the YF can provide enough fuel for a 258, it should be fine for the F134.

AFAIK Redline is THE importer of the Weber carburetors, and they put the kits together. http://www.redlineweber.com/

 

Thanks. I like the information you give, because it's deep. "Dimensional Analysis" is a term I haven't heard in a long time. Used a lot of that to get through school. Of course back when I did that was before hand-held calculators came out and I used a slide rule. Don't think I could do more than simple multiplication on one of them now. My first calculator was a top of the line (for the time) TI-59 which had plug-in magnetic strips you could program with formulae for different things. I had a file full of electrical formulae and another full of mechanical formulae, not to mention trig functions, etc. As I recall, that thing cost over $300. My, how far we have come, huh? Again thanks for the formula and doing the calc's for me. Have a good evening. Go take a night swim in your pool. I just got out of mine. 24,000 gallon with a waterfall. I love sitting under the waterfall on a hot day and drinking something like a Guinness Stout, or an Angry Orchard hard cider. Later.....