Information needed, F Head

I just bought a fairly original Arizona '59 CJ5, 134 C.I. with a T-90/OD. The thing runs terribly rich! It loaded up the muffler with unburned gas and blew the thing off! The previous owner had the carb pro rebuilt, the fuel pump quit so he put a electronic pump on. I put a regulator on the electric pump suspecting too much pressure, set to 3.5 lbs. It helped for a little bit, then the engine starved out. I have the shop manual and will adjust the valves, I ordered a new proper fuel pump, is it possible to Petronix the distributor (It looks like an Autolite). Are these old Carter YF carbs hard to rebuild? Any pearls of wosdom? Help!

Kelly in Tucson

 

Go solex!!!!!
Solves a lot of problems.The carb is easy to rebuilt.The hard is to find a good kit and do the job right.Not just clean it with fluid and fit the new kit.
In the past i have problems with a carter one PRO rebuilded and cleaned with ultrasound.Didnt want to adjust right.The problem was bad throttle shaft bushings that allowed air to enter in the manifold.

 

If you choose to keep the Carter they are not hard to rebuild and calibrate properly, I agree with blevisay that a sticking float would be a good place to start. On the YF one common cause of excessive fuel comsumption is that the pump diaphragm is old and seeping fuel directly into the intake manifold.

If the float is correctly adjusted the fuel pump pressure is correct thats the pump diaphragm is the first thing I would suspect.

When properly rebuilt and calibrated the Carters are capable of excellent all round performance,Worn throttle shafts can be shimmed.The solex option is also a proven alternative....................I just personally prefer the Carter YF.

 

I had the same problem, ended up getting a Solex, but kept the orig for sometime later? Then Sold it as the Solex proved itself.

 

:iagree: Probably the biggest issue with most rebuild kits is that they do not contain the proper fuel valve ( needle & seat ) For use on the F-Head the fuel valve seat orfice should be .076 dia and the needle should be a sping loaded three piece unit ( brass needle + spring + pin )

The later model rubber tipped needles and larger dia seat orfices can be used but would require a fuel pressure regulator between the fuel pump and carb inlet.

One other issue that I have ran into is that some vendors dont use the correct material to make the pump diaphragm, The diaphragm should be reasonably flexible,soft and supple........like a brand new unwashed cotton work shirt for lak of a better analogy, If the diaphragm looks and feels like a thin bicycle inner tube its too stiff, It also seems to have a memory and the manifold vacuum will not be strong enough to hold the metering rod down in the jet. Bench testing that I have done shows these diaphragms require considerably more vacuum to maintain contact with the lifter link and this results in running on the high speed step of the metering rod anytime there is less than 15"hg in the diapragm vacuum chamber........The short version in english is that fuel consumption will drastically increase.

Also many kits have a replacement pump diaphragm spring that is to heavy ( the kits with the stiff diaphragm tend to have this heavy spring ), Requiring an additional 2"hg of manifold vacuum to keep the metering rod in contact with the lifter link, Again contributing to poor fuel economy. There is no reason to replace the pump diaphragm spring unless it is broken.

I will check some of my old recorded part numbers on individual components.

 

I put a Solex on my 64 CJ 5 several years ago and now I think it is the problem. Stumbeling, backfireing some times and I must use the choke for the first mile. Has any one had problems with the Solex?

 

This weekend I'll get to checking the carb. The fuel pump (Bosch) is coming from Rock Auto ($34). I need to pull the distributor and get a Petronix...I'm no virgin to old iron, just Jeeps. I swear by Petronix. I have a pile of old carbs. I believe I have a Rochester single barrel or two. Simple carbs. The float, throttle shaft and needle/seat all are suspect on the YF. The PO admitted it never ran after the rebuild. I also have to fix his...ahem..."wiring" job. I have headlight, nothing else and it's not charging. Anyone have a good wiring diagram, the PO marked up the shop manual and I want to convert to a GM alternator with internal regulator (3 wire). Any suggestions? Who would have the proper rebuild kit for the YF? I have a early Studebaker YF, will it work? Sorry for all the questions. I've found the internet is where the folks in the know usually are... Thanks KM

 

By the by, what solex? A VW carb?

 

Originally Posted by Howard Eisenhauer
One thing that may have gone wrong is the "professional rebuild", most FLAPS rebuild kits don't have the right pieces in them for the YF as it 's used on the 134, you really need to get a kit from a specialist supplier.

H.

What suppliers are carrying the correct kits?

 

I am working on putting a small list of part numbers up that I have used and are correct, I know the " carburetor shop '' can supply the correct parts in kit form.

NAPA Part Numbers;
Jiffy Kit #2-5096
Spring loaded needle and seat as separate component ( .088 orfice, will likely require a pressure regulator ) #2-3724
Pump diaphragm as separeate component #2-4218

 

I ordered a kit from The Carburetor Shop, LLC (www.thecarburetorshop.com) on Sparky's recommendation. It's a CS-1822 for a Carter YF - $65.00 + $12.00 shipping. I haven't done the rebuild yet, but there are no instructions that come with it. You'll need to order by fax or telephone (no online orders), but you can verify kit numbers and pricing by e-mail. I just finished a re-wire (EZ) along with a Pertronix install and am pleased with both.

 

Hey DKillam Thanks for the Info.

 

i'm assuming they use the same carb? or is there a difference in carbs.. mounting or else wheres? i know the f and L are very similar engines but not sure how similar.. also anyone know if buying a solex, what of the linkage will have to be kept off the original carb? thanks

 

sorry, wasn't specific enough, (actually quoted too much of previous post) was wondering if the same carb is used between the L/F not the difference between the L/F and VW