willysmjeeps.com

Posted: **Mon Oct 18, 2021 4:42 pm**

I studied the Wes Album pics and read posts on the M38 YS637S carb. My understanding is there are two variations and one fake repo floating around out there in Parts Space.

Found this one on FleaBay for a fair price .... listed as 'Used' , which means it may even work.... or not. It does look clean if that means anything.

Because I have a well deserved reputation of buying the wrong M38 caca ... well, take a look. If I haven't screwed up (again) I have some questions.

Posted: **Mon Oct 18, 2021 5:16 pm**

Looks genuine M38 to me. Nice find. Rare and expensive.

Posted: **Mon Oct 18, 2021 5:35 pm**

Its legitimate. Looks good on the outside, no telling how the inside looks though. There is enough plating left on the linkages that I would think that carb hasn't had a ton of use.

Posted: **Mon Oct 18, 2021 6:00 pm**

Score!

Posted: **Mon Oct 18, 2021 8:18 pm**

Thanks to all. Looks like the real deal.

So:
* Slap it on and try it out next year when hopefully the jeep is running?
* Buy a master rebuild kit and have a local shop do the work?
* Follow the rebuild instructions and DIY. (probably not the best plan)
* Send it off for a major bucks rebuild $$$ ?

I am closing in on the big items. Not there yet.
Some bad luck with USPS. Hoping for good news.
Some good luck finding a few needed small items.

Slow motion. Slow motion.
Many things are coming together (I think).
Slow motion. Slow motion.

Posted: **Sat Oct 23, 2021 8:31 pm**

It is an M38 carburetor---it is also the early first version carburetor.

EARLY

LATE

Wes,

I have uploaded pictures I have of an early NOS M38 Carburetor and a NOS late Carburetor to my photos file. The date on the late carburetor is 10 / 65.

The early Carburetor has what looks like a “tube” on the outside of the center body and the late does not have it. The CJV-35s would have used the early carburetor and on the CJV-35 and M38 speck sheet, you can clearly see an early carburetor pictured.

The Manual on Carter Carburetors shows a picture of the early carburetor and the M38 parts manual shows only one part number—which is the same as the late carburetor made on 10 / 65. Since there is no mention of two different carburetors, the only difference must be visual.

Since I can’t seem to figure out how to add a photo in a post, and I just tried again, I would hope you would post them for me. The pictures are on the 2nd page.

Harold

Posted: **Sat Oct 23, 2021 10:55 pm**

Harold,

This is the second time an early & late version of the YS637S has come up. This would be a very good time to publish a photo series comparing the two different versions of the YS637S.

Thanks Harold!

Posted: **Sun Oct 24, 2021 10:12 pm**

The pictures should help identify the carburetors. If any M38 carburetors are found with the original brass ID tag, I believe they are date coded and with a good sampling, we may come up with a working change over date.

Thanks Wes!

Posted: **Mon Oct 25, 2021 5:10 am**

Thanks for the pics Harold. Thanks to all for the info.

Is the serviceability likelihood of this ‘used’ carb somewhere around slim to none?

Maybe just do a rebuild and move on to something else?

Posted: **Mon Oct 25, 2021 7:49 am**

Don, the detritus in the inlet is of concern, if it is incidental not so much. I'd pull the top, check for trash-if none check the float setting and give it a go.

Harold, I have one of the early 637's on the shelf in my spares..

Posted: **Mon Oct 25, 2021 8:49 am**

Thanks Rick. It can set on the shelf for a while.
Maybe it’s time to play with electricity.

Posted: **Mon Oct 25, 2021 9:27 am**

I posted about the two different m38 carbs quite awhile ago (in 2008). here are the photos from my photo gallery

if my memory serves me well, i remember poking a wire down that extra hole, and it seemed like it was blocked, a dead passage, but I may be wrong.

i did not take photos of the two base sections, probably because they were the same. I wish i did!

Posted: **Mon Oct 25, 2021 1:18 pm**

The YS637S carb is on the list of special M38 things that make us smile.

Posted: **Mon Oct 25, 2021 1:45 pm**

Mullens was selling the knockoff. In my M38 Fuel System sub-album you will find all of Gary's, Mullen's and my 637S photos.

Posted: **Tue Oct 26, 2021 5:39 am**

The ad did not include the term 637S and there was no pic showing the side with Carter YS so at first I was unsure. It was a Buy Now listing.
I don’t like the crazy numbers that pop up in an auction on these things. People will sometimes bid top dollar for a core.

I studied the album pics closely before buying the newly listed part then pulled the trigger and this time made the right choice.

The album pics have saved me cash and cursing but I have never
touched an M38 part other than the ones that came with the jeep and
the ones I buy ... so my education continues.

Don

willysmjeeps.com

M38 Carter YS Carb

M38 Carter YS Carb