How To ID A WWII 539S Carter Carb

[Chuck Lutz]

Frank Berg's photos of a crated GPW:

GPW Motor Oct. 1944 Rear.jpg (248.38 KiB) Viewed 2176 times

NOS GPW Motor Frank Berg.jpg (188.2 KiB) Viewed 2175 times

[Bill M]

I think you have something there Chuck,
the NOS engine photos particularly the ones of Ken Cerras' MB engine and with Richards beautiful NOS 539S look to be the flat black phosphate finish.
Here is the last NOS base I have. It is the phosphate finish with no colour additive and the aluminum idle port rivet plug like Carsten's.
That finish on Richard's 539S should be easy to replicate for those who are restoring carbs.

IMG_8203.jpg (238.63 KiB) Viewed 2123 times

IMG_8205.jpg (141.95 KiB) Viewed 2126 times

[Chuck Lutz]

Looking at the article in the CARBURETOR SHOP website about finishes....they say Carter used "zinc phosphate" on the steel.
Looking at the WIKI for "Parkerizing" they mention the following:
Zinc Phosphate = light to medium grey appearance
Manganese Phosphate = medium to dark
Iron Phosphate = black to dark grey, similar to manganese phosphate

so...if we scrounge up a couple body flanges....is there ANYONE here on the gee that does metal plating or has a connection so we can have a couple done up to see which more closely turns out like the NOS one?

I think anyone who does come up with a good replication of the final product will have a ton of them to do! maybe some of our weapons guys have had some of this done and can ask their guys about "zinc phosphate" for us?

Right after they come back from the machinist who will bush the throttle shaft openings!

[Tom Wolboldt]

Hi Chuck,

I noticed today that the round style insulator is shown in G-503 ORD 9 dated Jan. 15., '44.

[Chuck Lutz]

Tough to see, but I agree it looks to be the RIUND insulator in the January 15, 1944 SNL....I see that the March 10, 1943 TN 10-1348 shows the POINTED style....but again I have to say that since we are always suspect of the TMs using old pics especially when the two parts are interchangalbe and share the same part number...that the change could have occured prior to that printing...

What we need is for someone to check the Willys TMS to see the pics there of the exploded 539S and to see if the pointed or round one is shown. ....and WHEN the pic (if ever) of the round style appears.

Right now, the 1/15/44 showing the ROUND style tells me that around mid to late 1943 the change/addition of that round style occured and the lead time for photos, and printing pushed it to that time frame at least.

[David H. Morganthall]

Chuck, more questions but no answers:

Since the 698 bowl retains the 0-475 numbers, and the 636 has 0-614 does that indicate the sequence of manufature dates?

Second, I have some extra 539 pump links but they need the special washers. Do you know if they can be purchased and from whom?

Third, do you have any friends with Studebakers? I have a nice 1940 468S carb with the tag.

[Chuck Lutz]

David...

1) I really have no idea what the "0.475" or the "0-614" mean...so I have no idea if they refer to any chronological progression.
2) There is a CHEVY parts repop house back east that sells the stamped sheet metal keepers at FIVE for $15.00 I think...google for that.
3) Der Studie? Hmm....probably a website for those with the Studie Disease also....no idea who might need one.

[David H. Morganthall]

I was pondering numbers on castings vs. precise dates for the carbs.

[Chuck Lutz]

I think they hauled away the last dumpster at the St. Louis Carter factory a long time ago and the records went with it...the story on the introduction of each model of Carter (539S, 698S, 636 series) is for the time being only told by the many different models in one of the Carter Service Manual books...and even then, the original manual owner may or may not have updated his with each new bulletin....several I have looked at contained perhaps all, some, or different bulletins for the various Carters produce in the 30's, 40's and 50's.

You have to have a few of those big books to even try to get a handle on all the carbs, the numbers and the year/model applications they were used with. That will give you a pretty solid chronological order since the NUMBER is at least sequential, even if the application is not.

For the record, the 539S is the ONLY factory installed WWII carb for the GPW and MB. It seems to be the one purchased by the gov't for replacements in WWII also.

[David H. Morganthall]

BTW Chuck,

I just bought some plating supplies and will be trying to replicate the finishes. The only base I have that still has the factory finish also has the factory lacquer coating on it. It is not a light grey but fairly dark since it was protected more than than the ones pictured above. I realize not all had this lacquer and am trying to determine dates for that as well, but finding a similar finish that does not peel or dissolve in gas is proving difficult. If my efforts succeed, I wil be able to help others with replating/refinishing.

[Chuck Lutz]

The factory finish is a grey phosphate type finish or a black oxide finish....from the grey to the black and not shiny at all and not a painted-on product. Carter sold a product to be used in the overhauling of the carbs that was a black finish, possibly a shiny laquer appearing one but they were not produced as a COMPLETE carb from the factory with that finish. Since an overhaul shop was not equiped to do the phosphating process but could PAINT the flange body, this product was made available.

I would not paint a jeep 539S with the black paint for a factory appearance....I would seek a shop that can do the phosphate process, THEN have the bushings installed for the throttle shaft.

For a motorpool jeep, the black paint is OK.....I think....because I am not sure when this product was made available....

Carter Base Paint.jpg (53.5 KiB) Viewed 1898 times

Here is one of Brent Mullins in-the-box 698S carbs from the post WWII era...note the flange body appearance...

Carter 698S Brent Mullins.jpg (45.46 KiB) Viewed 1897 times

Here is an NOS in-the-box flange body from Derek's collection:

Carter 539S NOS Body Flange DE.jpg (67.7 KiB) Viewed 1897 times

[David H. Morganthall]

Chuck, that whitish appearance I believe is the result of age and moisture. The base I have which had the factory lacquer applied is much darker and more even in color similar to the dark spots left on this base. I should have my kit next week and will post pics; then if you folks like the results you know where I live.

[Chuck Lutz]

Looking at Carter documents, they used either a zinc phosphate, a manganese phosphate or another phosphate....they did NOT use a paint....they did NOT use any lacquer.....if you are rebuilding them, you can paint them David but....Carter did NOT use that on factory 539S carbs...your treatment will result in what Carter provided for rebuilders at the time to "restore" a flange body without seeking a plating service to spiff up the flange body, but it is NOT...NOT...NOT what they did with factory produced 539S carbs for the g503.

So again, your process delivers a "rebuilt" appearance and the phosphated finish delivers a "Factory" as-delivered-as-installed appearance.

The choice of finish is up to the buyer and what they are looking for.

[Bill M]

Chuck, I would be interested in seeing the documents that specifically mention the Factory finish for the 539S base.
Bill.

[David H. Morganthall]

Hey Chuck, hold on to the judgement before seeing the results. If you read more about finishes you may discover that yes Carter did use a gas proof lacquer at certain times. I will be doing the factory type process, but using modern techniques which will hopefully mimic the real thing. I will NOT be trying to do any clear coating at this time since I want to allow the natural oxidation to occur as did on the one in the photo.

As a footnote: I have acquired a couple top sections that have been anodized BY CARTER, but just as the base above has I think changed over time, on my parts the anodizing has migrated to the cad plated parts giving them a gold tone. It is impossible to judge the original results based simply upon a 70 year old sample that WAS NOT held in a controlled environment for 70 years. The whitish look does happen to any type of black oxide over time and I have read accounts backing this up regarding 539 carbs.

I think we are all enjoying kicking this around, so please keep bouncing back with your thoughts.