Vinegar ate my carb!

Or at least part of it. I'm helping a friend with his '79 Suzuki GS425. I broke down his carbs and threw a bunch of parts into a container of vinegar. I've done this many times before including with whole carb bodies.

These carbs are BS34s and I think are similar to those on XS bikes of the same vintage. They have a separate little choke body that holds the plunger and that is screwed onto the side of the carb. I tossed those into the vinegar, too.

I did leave them for quite awhile - 24 hours - but I've done that before and never had a problem. The bowls and all the little brass and steel stuff was fine, but the vinegar just ate those choke bodies! I mean chalky, scraping away powdery crap, big pits, etc. There's still metal underneath and I could probably get the outside of it cleaned up good enough, but the inner passageways are toast. Too risky to try using them.

The bodies of these carbs seem to be a different alloy than those on the XJs. Still, I'm paranoid now about using vinegar. Has anyone else had something like this happen?

 

I followed bad advice of boiling my carbs in simple green. Actually boiling, not just soaking em. turned em black and dusty, didn't compromise the metal though.


a plating shop is a good place to turn to in these situations, they know a lot about metals and chemicals, not to mention they have chemicals to remove the deposits, etc. they have chemicals that are not for the do it yourselfer.

 

Honestly these pieces are not salvageable, I'm afraid.

 

Bummer...But, you may be LUCKY....I think I just so happen to have a complete rack I will sell you.
I bought it for a project that I just can't seem to get to. Plus....the EFI thread has changed my mind and if I ever get back to it, I'm going EFI.

I'm 95% sure they are BS34s off a Suzuki....no idea of the year.
Drop me a PM with your email address and I'll snap some photos to see if they would work.
I'll sell the complete rack. I haven't touched it since I took it out of the shipping box 2 years ago. I'll take the loss and $100 will get it to your door if you can use them.

 

Im not familiar with the little "choke bodies" you are referring to. There is NO possible way the vinegar for 24 hours would dissolve metal parts, nope, uh uh, not gonna happen. The parts must be made of something else, or were already so oxidized from time and the elements that what you simply did was soften up what was already shot and just barely holding together to begin with.

Vinegar or as many people like to use Lemon juice is a VERY WEAK acid and is perfectly safe to use on metal parts. You just might to make sure your parts arent already crumbling in your hands to begin with.

 

Well, you can say it's not gonna happen, no possible way, etc.....but apparently it DID.

vinegar is usually a 5% acid solution, but it is possible to get higher concentrations. Obviously, it seems there was a pre-existing condition, but that's basically beside the point. The point is the carbs have been etched beyond use and he needs another set.

I don't use an acid cleaner....I use a base cleaner, myself.

Dave Fox

 

my point is the damage was already there, the metal was already heavily oxidized and probably on the verge of collapse before the acid was applied. Probably any solution would have done the same thing. Its no reason to worry about using vinegar as a weak acid solution in the future.

 

I think the Vinegar did you in.
Even diluted 50:50 with water is still strong enough to do some damage.

I have been sent some really nasty Carbs to service over the years.

I haven't seen any with a degree of oxidation that resisted being brought-back to looking fine after being sent-out to have the dull gray powdery glaze and dark green fungus and tarnish stripped off at a Media Blaster.

Baking Soda, Plastic Beads or Walnut Shell will strip-off neglect and restore the alloy to how it looked when new.

 

I have to agree. Vinegar works great, in 2~3 hours. If you left someting soaking in it for 24 hours, it is possible for damage to occur, depending on the alloy.

However, it is more likely that it simply "ate" the corrosion, and the parts were already toast.

 

I wonder if those parts are pot metal.

I was removing rust from the tank on a 1982 Honda CX500. The petcock nipple on it had an uncommon thread I didn't have a cap for so I did it with the petcock on, which I've done before. The acid ate right through the valve (the part with the ON, OFF, RES) handle without damaging the body at all. On inspection I think the valve itself was pot metal, not aluminum.

 

+1

 

Thanks to everyone who has posted to this thread so far. I'm able to provide a little more info and some pics now.

Here is the little choke body and I think you can clearly see that this was not just surface corrosion that was removed by the vinegar. In fact, it looked perfectly fine when I tossed it in. Now, not so much.

This is what I've been wondering as well. For comparison and to test your ideas about how corrosive the vinegar might be, how long to soak, etc, I took a junk XJ650 carb body (BS32) and tossed it into the same container of vinegar and left it for 24 hours. It looks fine. Here's a photo of the 650 carb on the left and the not-yet-cleaned Suzuki (BS34) on the right.



Because of the angle at which the photo is taken it's a little deceptive in that the BS34 is actually/obviously bigger than the BS32. You can see where the choke body mounts on the side of the Suzuki carb. I'm not sure if you can really tell the difference in the materials of the two carbs or not. The BS34 is just duller, darker, and MUCH heavier. That caught my attention when I took the pics just now, so I weighed them. The BS32 weighs 356g and the BS34 is a whopping 758g. They are definitely not made out of the same alloy. Could the entire carb body on the Suzuki be pot metal?

 

More than twice as heavy? It shore ain't aluminum; or if it is it's one FUNKY alloy.

Are the Suzuki carbs Mikunis (as in SAYS Mikuni on them somewhere) or just Mikuni-pattern?

That degree of destruction is frightening.

 

Well, the Suzuki carb bodies themselves have no identifying marks on them - such as the embossed symbol seen above on the side of the XJ body. However, the "hats" say Mikuni Kogyo Co. on them and the Clymer manual identifies the carbs as Mikuni BS34s. Seems pretty definitive.

 

The Mikunis on my 550s have "Mikuni" emblazoned on them as well.

They might be Suzuki-built under license from Mikuni, using gawd-only-knows what metal, with some Mikuni-sourced parts.

 

Well, I'm going to be real careful from here forward, I'll tell you that. It all makes me curious about the properties of various alloys. Why are these so heavy? Are they full of lead? Does the type of acid in vinegar break down lead or is there some other specific compound that can't handle the acid? I might ask my friend down at the welding and metal fabrication shop. They know a lot about different kinds of metal.

 

Do a "Google" search on acetic acid, the acid in vinegar.

This is from the Wiki page: "mildly corrosive to metals including iron, magnesium, and zinc, forming hydrogen gas and salts called acetates. Aluminium, when exposed to oxygen, forms a thin layer of aluminium oxide on its surface, which is relatively resistant to the acid"

It might almost be worth taking the ruined part to a metallurgist and finding exactly what it IS made from.

 

I discussed this with the welder here in the complex this morning.

According to him, pot metal has a lot of zinc in it. According to Wikipedia pot metal is primarily zinc. The article also says that pot metal is susceptible to damage from airborne acids. I presume soaking it in acid can also damage it :lol:

A quick search shows that zinc has more than 2.5 times the density of aluminum.

I see what appears to be crystal grains on the RH carburetor. They remind me of the grain visible on the underside of the die cast cars I had as a kid.

 

Well there's your answer.

They're "Hot Wheels'" Mikunis!

 

Ha! Who knew? Very interesting. Thanks, guys.

I think I'm going to post a link to this thread over on the GS site for the benefit of other unsuspecting would-be carb cleaners.