Carter ys 950 rebuild questions

bpenkala · Post by **bpenkala** » Tue Jan 29, 2013 12:08 am

I've seen lots about carter ys 950 carburator rebuilds but I have a few questions that I haven't seen addressed.

1. How is the long (about 3") brass tube in the horn removed and new one installed? My rebuild kit has one but I am concerned about removing it because it seems a bit fragile. The outer brass tube is easy (unscrew) but the inner thinner tube seems pressed into the horn.

2. My carb doesn't seem to have the "discharge ball and weight" in the main body of the carb but the rebuild kit has replacements. Problem is I don't know where exactly they go. I think I see the hole but there is a brass tube in the hole (recessed about 1/8 inch) and I don't know if I should take it out. Does anyone have a top view photo to show where this goes?

3. How are the various plugs removed - or should they be? I am concerned about installing the new plugs and getting a good seal.

Thanks for any help!

Post by **wesk** » Tue Jan 29, 2013 1:26 am

1- Unscrew the outer tube. With a pair of soft metal jawed (aluminum or brass) pliers it takes very little grip pressure and very mild pull pressure to remove the skinny tube. It is an interference fit but can be pressed in by hand. It is only installed to a depth of about 0.113". If you have new ones then you should use them. The old ones are usually a bit corroded and may be coated enough to alter the volume of air bleed. These tubes and the holes in which they are installed need to be thoroughly cleaned and checked with compressed air for any blockage. When installed the tip of the small tube protrudes from the large tube about 0.285".

2-Discharge check ball & weight installed as shown below.

In this photo there is already a weight & ball in the hole. That's a new weight & ball I have illustrated outside of the hole.

3-In order to insure all passageways are unblocked or un-restricted you should pull the plugs. Use an easy out set and use the appropriate drill and easy out to pull them out. Make sure the hole's clean and when done with the soaking, cleaning, repairing if needed then install the new plugs.

Have you downloaded a PDF copy of the Carb overhaul manual chapter and the YS950S spec shett on our downloads page?
http://www.willysmjeeps.com/v2/modules. ... tit&lid=71
There was never a manual chapter for the YS950S because the Carb manual TM 9-1826A was published Dec 1952. You must use the YS637S chapter together with the YS950S spec sheet. The carbs are nearly identical except for bore, throttle boddy orientation and vacuum passageways.

I have a few photos in my Album as well.
http://www.willysmjeeps.com/v2/modules. ... _album.php

bpenkala · Post by **bpenkala** » Tue Jan 29, 2013 11:16 pm

Thanks for the prompt reply! I looked closer and found the ball and weight in my carburator - it was corroded so much that it looked like a hole that just ends.

I did get a copy of the carb documents and they will be helpful in the rebuild. I am in the process of soaking the parts and will hopefully start rebuilding soon.

bpenkala · Post by **bpenkala** » Wed Jan 30, 2013 12:42 am

After I soak and clean the carb is there some kind of coating to apply to help protect the metal - I see some are more of a bare metal and some seem to have various shades of gold color on them.

Post by **wesk** » Wed Jan 30, 2013 1:30 am

The professional overhaulers use chemical or electro-static plating processes to protect the metal from corrosion. Usually cadmium or zinc. You can look for a local plating company to plate the housing assemblies for you after you clean them.

Do not try to use spray on coatings or paint since they will quickly deteriorate and leave residue inside the carb.

bpenkala · Post by **bpenkala** » Wed Jan 30, 2013 10:16 pm

Do you know what type of metal the main housing parts of the carb are made of? The part that attaches to the engine is steel but the other two parts I'm not sure of.

Also, there are still a couple brass tubes in the housing - are these okay to leave in during electroplating? There are no replacements in my kit so I assume they should not be replaced.

Thanks again!

Post by **wesk** » Wed Jan 30, 2013 11:32 pm

Most carb soft metal bodies are zinc. The coating used is chromic-acid. The light coating it leaves on the parts is zinc chromate.

bpenkala · Post by **bpenkala** » Thu Jan 31, 2013 8:14 am

There are a couple of brass parts (tubes set into the body of the carb) - will these be okay to leave in during the plating process?

Post by **wesk** » Thu Jan 31, 2013 10:47 am

The "Hi-speed nozzle" and the "Pump jet" are not listed in the parts breakdown which means they are not available and originally came with the main body assy. To remove them would require an odd puller or a fabricated threaded puller and some heat which would most likely damage both tubes.

I do not think they will suffer from the short exposure to the chromic-acid, since it is used commonly to bright dip brass, bronze & copper, but you should secure the professional rebuilders/plater's advice. I have dipped many carbs without removing pressed in brass tube with no damage to the brass. The dip time is only 2 minutes. I also checked with a local shop that overhauls carbs today and they still use Chromic-acid dipping and they still leave brass tubes in place. I have used Alodine for corrosion proofing aluminum and magnesium for years.

Here's their web site:http://www.henkelna.com/cps/rde/xchg/he ... 7571448974

"The Carburetor Shop" would be a good place to start: http://www.thecarburetorshop.com/Orderinfo.htm

From this web site: http://www.chemical-supermarket.com/Chr ... -c169.html

Chromic Acid Formulations

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Formulation: Chromium Trioxide dissolved in water

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For Magnesium Cleaning:
The treatment of magnesium metal differs from the treatment of Aluminum in that in the case of heavy corrosion, two solutions must be used. For light surface corrosion, only one is necessary.

Immerse parts in an alkaline cleaner until parts are chemically clean and free from waterbreaks.

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· Chromium Trioxide 1.6 oz. for 8 fl. oz.
· Put 7.0 oz. of water in beaker and pour in the Chromium Trioxide crystals and mix the same as the aluminum solution.
Surface must be clean and free of oil and dirt. On magnesium, allow the 20% Chromic Acid to stand for 2-5 minutes or until it has stopped working (or bubbling), wash with clear cool water to remove remaining acid and dry with an air hose or wipe with a clean cloth until dry.

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exercised in mixing the chemicals in this step. A chrome pickle solution (5% by weight) is made from:
· Sodium Dichromate - 1.5 oz.
· Nitric Acid - 1.5 oz.
· Water to make 8 fl. oz. total
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For Glass Cleaning:
This is a solution of chromium trioxide (CrO3) in concentrated sulfuric acid (H2SO4). A pre-measured mix is available under the name "Chromerge,” which should be treated in the same way as aqua regia or other acidic peroxide solutions.

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bpenkala · Post by **bpenkala** » Fri Feb 01, 2013 11:05 pm

Any suggestions for a shop that will refinish my carb parts with a corrosion protective coating? I've been calling around and don't seem to be getting anywhere.

Post by **wesk** » Sat Feb 02, 2013 12:05 am

1- Have you contacted these folks yet?
http://www.thecarburetorshop.com/Orderinfo.htm

2-Post your location so someone will know if they have a shop near you.
You can always have your location showing by going to your profile and insert the state or city you are in.

bpenkala · Post by **bpenkala** » Sat Feb 02, 2013 12:20 am

I did contact http://www.thecarburetorshop.com/Orderinfo.htm but they only supply rebuild kits - they stopped rebuilding to focus on parts.

My location is Santa Barbara, CA if anyone knows of a carb rebuild shop - Los Angeles area is okay.

whydahdvr · Post by **whydahdvr** » Sat Feb 02, 2013 7:02 am

Bpenkala,
I used to live in SB. While I don't know off hand of a good carb shop go to one of the Fast Lane Autolube's and ask. The owner is my uncle. They may be able to point you in the right direction.
There used to be a good shop on one of the side streets off of Milpas, not far from Gutierrez, maybe a block or so off, possibly closer to the 101, right on a corner, owned by brothers.
I moved away back in 1999. I may have another lead as well but have to see if I can track down a name from relatives out there. Shoot me a PM if you like.
-Josh