Carb Slides issue

[Suzuki_dog]

Opened up the carbs on my Katana and found something interesting in the Carb slides:




Anybody ever seen anything like this? Kind of flakes off with the fingernail. Going to try some paint stripper or thinner, would there be any reason to paint these black? Or maybe a teflon coating? Maybe a dumb previous owner?

[92xjunker]

Just normal build up. Carb cleaner should remove that.

[sixdog]

Wow, never seen anything like that...number 4 slide is a champ!

[Suzuki_dog]

Just normal build up. Carb cleaner should remove that.

Thanks. Just curious, though, a build-up of what?

[RobertTravis]

Thanks. Just curious, though, a build-up of what?

Varnish from the fuel. A little squirty squirty and rubby rubby will clean them right up...unless some toad painted them

[Suzuki_dog]

Varnish from the fuel. A little squirty squirty and rubby rubby will clean them right up...unless some toad painted them

Never seen varnish that black... at work, will start cleaning tonight when I get home.

[Kreylyn]

When you have varnish and micro particles from wear, you get a nasty black coating. So, it's not just varnish...

Paint would be more like a liquid goo when dissolved with a cleaner vs varnish and particles would be more paste like as you would still be able to feel the particles in it.

You can scrape some off, add a little carb cleaner... see how it reacts to know for sure.

Krey

[Suzuki_dog]

All clean and back together. A friend of mine found out what it was. Its a factory applied coating to prevent corrosion. He found where someone else had came across the same thing. Apparently the Zinc base metal that the carb body is made of will corrode with the slide base metal of Aluminium. Just add atmospheric moisture and a little time passage of no use and they will stick. These carbs had not been off of the bike since I owned it (never needed to until now) and in a previous life, it had spent alot of time outdoors next to an ocean in Florida. I'm sure there was enough moisture where it was to do this. Anyway, an interesting thing to see.
Thanks.

[RobertTravis]

Are you going to recoat them with something? I don't have any suggestions for you...but galvanic action could still be an issue.

[Suzuki_dog]

Are you going to recoat them with something? I don't have any suggestions for you...but galvanic action could still be an issue.

I was not planning on it, I have no idea what to use. I have other similar carbs and they have not been coated.

[92xjunker]

Gun bluing might work there. It's a chemical coating that is baked on, that can be done at home. I've researched zink recoating, it's not an easy task and could leave you missing a part. Prep requires a lot of work. A nylon/ plastic coating would be ideal but, who does it?