Ford Holley Carb.

just wondering whats the common symptom/complaint when folks have issues and can not fix these carbs....

I have seen were folks bring them in and the metering cover gasket was a issue but i have not had a problem with this issue with TISCO kits,,, i have had to trim a new gasket were its a little fat but that's it... When i had to fix'em (were folks have already fudged it up) I just made a new gasket... If the new gasket they installed was off once they nailed it down it fudged it up...

It may be two different models of carbs that use different gaskets,,, what I am work'n on is 2/3000 3cyl engines

The other issues I have seen is the accelerator pump is stuck but a plumbers wire brush cleaned all up well...

they also have a check ball for the accelerator pump and if its bad it will run rich,,, no help for a bad check ball as of know of yet,,, would like to have a bad one so I can disassemble it but all the check ball assembly's I have ran into have been good...

bout all I have not figgered out about them is what the ell is the spring for that goes around the pin that retains the float,,, does it help open the float are does it help seal the needle,,, got me all I can come up with is it keeps a little tension on the float/pin so it don't bind up in either direction..

the few that I have fixed that were not fudged up by a dufus had allot of grit in the accelerator pump circuit,,, have yet to figger out were the sand/grit came from,,, the rest of the innards of the carbs were clean so how did all this sand/grit git into the accelerator pumps circuit when the rest of the carb showed no sign of mortar mix...

Hobo:

The NLS spring was intended to help prevent the float sticking against the sides of the float bowl if the float drop adjustment is not properly performed (as is nearly always the case) as was/is a common problem with the earlier MS carburetors.

Unbeknownst to the Holley designers at the time and unbeknownst to everyone at this time except me and now you, the spring also helps to prevent the float pivot pin from vibrating and wearing the pin bores in the die cast air horn.

The vibration of the three cylinder engine in conjunction with the soft die cast air horn results in wear of the float pivot pin bores rendering accurate float adjustment impossible.

As you know, the Holley carburetor is sensitive to float adjustment due to the accellerator pump and sensitive metering system. Unless the float is properly adjusted, the engine will not perform as intended.

Metering gaskets are also a source of problems with the Holley carburetors but a subject for a different time.

Merry Christmas.

Dean

Hobo &/or Dean......as long as we are on springs.........what about this on a tsx813 that looks like it is in a position to help the float float? :?

Hobo &/or Dean......as long as we are on springs.........what about this on a tsx813 that looks like it is in a position to help the float float? :?

I was trying to visual the effect the spring would have on a gravity flow set up but the 3000 has a fuel pump so I was trying to sell myself that the spring somehow overcame pump pressure,,, I could not make that sale to myself,,, nor on the 33 in the pix,,, It is a EZ sale that's its a shock absorber/anti ware/d-hang'em device ,,, your thoughts ,,,,it will be interesting to hear Deans...

Being accustomed to being able to look down the throat of a carb sure nuff takes allot of the guess work out of a rich idle condition,,, most of the time you can see were the false fuel is being delivered,,, a up draft takes one of my silver bullets away...

I stumbled on the accelerator check ball/valve/tube assy only cuzz I could not blow thru the assy nor feed a wire thru it,,, after I removed the tube it hit me it was the check valve for the accelerator pump and a common unmetered source for a rich idle (most common complaint) condition on a down draft carb,,, then it hit me (like the lead in solder smok'n up my brain) that I had never seen this mentioned when folks have talked about issues with this carb...

I would say all the automotive kits come with parts to replace the accell pump and check off assy.

I know sometimes you get a uncopertive carb but so far i have seen no reason this type of holley can not be fixed as long as good fit'n parts could be had,,, I wonder if the check valve assy comes in a CNH kit :?:

The other issue is the metering valve gasket,,, all the kits I have ran into the bowl gasket and the metering valve gasket are cut as one gasket not to seperat gaskets like i see folks tote in the door

i was always taught that the gasket should be in plave when adjusting float on auto carbs. i don't know about the tractors.

Hobo:

If memory serves, the early Holley carburetors had an individual gasket for the metering plate while the later redesigned carburetors used a single float bowl/metering plate gasket. Complicating matters further, some metering plate gaskets do not have all holes in the correct positions, perhaps due to the use of incorrect gaskets during a prior rebuild. It appears that all of the inexpensive aftermarket Holley carburetor overhaul kits are the same regardless of the carburetor version.

For this reason, I ALWAYS bite the bullet and pay $80+ for the correct overhaul kit from CNH. The CNH kit includes everything needed to properly overhaul the carb providing that the float pivot pin holes are not worn egg shaped.

Dean

Dean

(quoted from post at 20:55:05 12/25/09) Hobo:

If memory serves, the early Holley carburetors had an individual gasket for the metering plate while the later redesigned carburetors used a single float bowl/metering plate gasket. Complicating matters further, some metering plate gaskets do not have all holes in the correct positions, perhaps due to the use of incorrect gaskets during a prior rebuild. It appears that all of the inexpensive aftermarket Holley carburetor overhaul kits are the same regardless of the carburetor version.

For this reason, I ALWAYS bite the bullet and pay $80+ for the correct overhaul kit from CNH. The CNH kit includes everything needed to properly overhaul the carb providing that the float pivot pin holes are not worn egg shaped.

Dean

Dean

Click to expand...

Does the CNH kit have the check ball/valve/tube assy The TISCO kit CKPN9590B did not but the kit was of good quality

I spec the check ball/valve/tube assy would fetch a mint,,, mite be the big difference the price...

Before i order up a kit I would check the check ball/valve/tube assy ,,, if its bad the TISCO kit would be a waist of money... theirs just no way to get around a bad check ball/valve/tube assy as I know of....

Mite take a look on the CNH site to see if its avalible...

Sometimes it easier to fix a common problem if you are aware its giving folks a fit,,, you rub on it more,, take the time to check it out better,,, accelerator pumps are not as common in tractor carbs and i spec overlooked especially when theirs no mechanical linkage work'n the pump

They do list it separate 18A

Valve Assy., Accelerator Pump Discharge, No Longer Serviced NH-E., Start Year: 10/01/1966
C5NN9N521A
1 Needed for Job
$18.06 Avail in 3-5 business days

I figure it this way...
1. It was ok - for awhile. The Holley obviously wasn"t a bad-running carb when it was new or Ford would"ve ditched it and not let it off the factory floor after the first year or two.
2. But it"s not ok after awhile/Majority rules. It obviously often has problems as it ages. It is a pattern failure of the breed. And, while some on this board may not have had to fight the problems, I"ve also noticed something as we"ve shopped around for another 3000 (a rebuild candidate): every running Holley gasser that we"ve looked at or called about has had the "will-only-run-at-half-choke" problem. Every one. Some owners even think it"s normal.
3. Experience rules. These carbs have been in the field for up to 45 years. And there are untold tens of thousands of hours of tractor-wrenching experience out there, and hundreds of years of that experience shared on this board. If there was a known and simple fix, it would have been found and shared. For me, one big nail in the Holley coffin was the now-almost 5-yr old link from Zane, below (I"m assuming that others also know Zane from the N forum here).
4. Even Ford threw in the towel. I also fought the Holley on our 3000 after we bought it a few yrs ago. I rebuilt carbs from when I was ten, and knew my way around things, and this bugger got the best of me. I was reluctantly going to bite the bullet and buy a Zenith, after reading about it on this board, but I still had my doubts. But as I plowed through the CNH carb and governor parts lists - which weren"t on-line at the time - I found that the Holley is NLA; only the Zenith is available from CNH. So, even Ford/CNH gave up on the Holley.
5. Zenith works. The changes in our 3000 were just amazing. And that carb still works great, years later.

I will say that I admire anyone who can get a Holley running ok and keep it running that way for any length of time. We"d be $300+ richer if I could"ve done it.
Zanes opinion of Holley

I have always said that those who complain the most about em can"t properly repair them. we used to have two Ford dealers close by, and whenever they would remove a holley and replace with zenith we got the old holleys for free, gotta love that. The worst ones that I have had to repair are the ones that have been given an attitude adjustment with hammer, wish the operator had just used it on his head instead. And yes the ones with the float pin holes egged out are usually missing that little spring, ie. last guy didn"t have a clue what he was doing. There are alot of automotive mechanics that can"t fix a Holley on a car either and cuss them aswell.

theirs not much I can disagree with about you post,,, nuttin much I can make a good argument with about what Zane has to say and I spec Zane will admit a old dog can learn new tricks...

Until the last few years even the mystery about how the old M/S carb works seemed to be a secret,,, it took some good folks not will'n to accept failure and question the normality repeated acceptance of failure...

Carb work is more than spray wipe and go,,, sling a few new gaskets at it if it don't work its trash,,, you know that...

My time is money,,, if someone totes one of these in the door they mite as well buy a replacement as it may be a draw on the price verses the cost of a replacement (close anyways) I do not work for tips tho do take tips

Before I took on the fight with this carb I confirmed all other operating systems were in top notch operating condition to rule out all but the carb,,, I would question other tinkers ability to eliminate other possibilities and declare the carb junk if a clean up and a few new parts don't fix the issues....

Time will tell,,, at this time I can not see how it could run any better ,,,it ran terrible before the valve adjustment, new tune up parts and confirming the dist controls were in work'n order,,, I still had the same issues so it was time to dig into the carb even tho I knew it was a carb issue from the get go with something to do with enrichment under acceleration...


I will make a statement and folks may not like it,,, you can not beat a carb with a accelerator pump. (long as it works) I have considered adding a external acel pump to other tractor carbs that I have trowed the towel in on...

I spec that's why a replacement wins out,,, folks never knew are can not remember how good it ran when all was right,,, I will not know for sure till I get it all back together,,, I have the water pump off going to put a axle pin and bush'n ,,, may go for the kill and clutch it while I have the front end off (PTO clutch is stuck) and need to pop the lift cover off cuzz its hard to maintain position control and in cold weather it takes the lift 5 min to start to operate, (warm weather it lifts cold),, I know the pump is not loosing prime cuzz the loader works great right off the bat (loader runs off the tractor hydraulic pump)

Properly set up the Ford Holley tractor carburetor is superior to all other tractor carburetors used by Ford and, no doubt, all other manufacturers.

That said, the Holley carburetor is much more sophisticated than other tractor carburetors as Ford was attempting to make the gasoline powered tractors of the vintage as economical as possible given that the industry was rapidly changing over to diesel engines.

In order to reliably meter fuel at the desired more lean mixtures while, at the same time, delivering good throttle response and idle characteristics, Ford/Holley incorporated both an accelerator pump and a vacuum spark advance in the era. This was a significant departure from other gasoline tractor carburetion systems then or since as tractor carburetors have always been rather crude, brute force systems, whether MS, Zenith or others.

Unfortunately, the agricultural service industry, accustomed to the simple, brute force tractor carburetors of the era did not recognize that the Holley was a different animal and could not be serviced/repaired in the cavalier fashion that had proven satisfactory in the past. Hence, the popular reputation, deserved or otherwise.

For a couple of decades, few in the automotive service industy could properly overhaul a sophisticated automotive carburetor such as a non electronic Rochester Quadrajet or Varijet. Very, few ever mastered servicing electronic versions of either. (I mastered both.) Is it any wonder why few service techs in the agricultural industry mastered the Ford/Holley carburetor, even though it is much less sophisticated than late automotive carburetors, let alone electronic versions?

There is nothing wrong with the Zenith carburetor used as a common replacement for the Ford/Holley but it will not deliver the economy that a properly functioning Holley will. Fords mistake regarding gasoline powered tractors in the Holley era was marketing rather than engineering.

Dean

Well said, Hobo.

Dean

Bingo!

Dean

Hobo, I was working at a Ford dealership when these tractors came out new. In less than a year or over 500 hours that D### carburetor acceleration pump was worn out. The problem with putting an excellaration pump on a tractor is that the governor is constantly moving the throttle and thus the acceleration pump too and the one on that 3 cylinder tractor is badly designed. It is strictly metal on metal and aluminum to boot and wears fast. Pretty soon there are wear patterns in the bore of the acceleration pump that causes it to hang up and not move. I tried honing out the bore but then the piston was too loose and the vacuum that is supposed to operate it was lost by the too big clearance in the piston to bore. If they had used a diaphragm pump it may have worn out just as fast but that could have been replaced and been back in business in few minutes but I never did figure out how to fix one of those acceleration pumps. To make myself look really smart and if the tractor wasn't going to be used for heavey work I just set the choke cable so the choke was partially on all the iime and the engine would not stumble when acellerated. Sneaky huh?

Zane

(quoted from post at 03:55:39 12/27/09) Hobo, I was working at a Ford dealership when these tractors came out new. In less than a year or over 500 hours that D### carburetor acceleration pump was worn out. The problem with putting an excellaration pump on a tractor is that the governor is constantly moving the throttle and thus the acceleration pump too and the one on that 3 cylinder tractor is badly designed. It is strictly metal on metal and aluminum to boot and wears fast. Pretty soon there are wear patterns in the bore of the acceleration pump that causes it to hang up and not move. I tried honing out the bore but then the piston was too loose and the vacuum that is supposed to operate it was lost by the too big clearance in the piston to bore. If they had used a diaphragm pump it may have worn out just as fast but that could have been replaced and been back in business in few minutes but I never did figure out how to fix one of those acceleration pumps. To make myself look really smart and if the tractor wasn't going to be used for heavey work I just set the choke cable so the choke was partially on all the iime and the engine would not stumble when acellerated. Sneaky huh?

Zane

Click to expand...

Yel I will say you worked your way around the issue,,, not so much Sneaky but improvising ,, making the best with what you had to work with... time will tell but I am gonna play out what i have for now,,, it will only see 20 hrs of work are so a year,,, hopefully this one has been stuck for a long time cuzz I did not find any ware in the bore..

Thanks for adding your experience,,, I will take that into account on the next one I run into and not waist my time if it shows excessive ware beyond original spec....

Carb work on cars/trucks got interesting the last 10/20 years they used them as they were trying to meet emission standards....

I think I can get my hands on a S&S carb with a acel pump and make a 3000 purr like a kitten 8)