Other What causes this level of corrosion?

[LeftysRule22]

I recently bought a waveraider with a "bad crank" The engine came disassembled and had been left outside long enough to rust over. After looking at the crank, despite the rust, it looked fine. Cases look great, cylinders look great, pistons have zero signs of wear, and the head is mint. So obviously this guy had no idea what he was doing and ruined a perfectly good engine.

That left the carbs, and sure enough they were packed full of crap. What bothers me is that the diaphragms were actually melted to the carb body. Not only that, but the diaphragms are stiff and crusty all over - no elasticity in them at all. Every metal piece has an obscene amount of rust and white corrosion... Now i have to figure out how to get the corroded stripped screws out - joy. So what gives?

 

[Lucaumpits]

I see salt in there

 

[LeftysRule22]

I wasnt sure if it was salt, or something else. It feels like talcum powder, very fine and smooth.

 

[Crab]

just get some good used carbs.

 

[LeftysRule22]

I dont need carbs, just was wondering what causes a diaphragm to melt like that.

 

[227]

I wasnt sure if it was salt, or something else. It feels like talcum powder, very fine and smooth.

Those carbs look like they were submersed in salt water but thats not necesarily salt in your carbs. The majority of people think salt is what damages a boat/watercraft used in the ocean when in fact its not. We put salt on our food, its not toxic. Ocean salt water contains tons of calciums and other elements which create an extremely harsh evironment for engines, carbs, electronics, etc. That is most likely what you're seeing in your carbs

 

[LeftysRule22]

Too bad, was hoping these would be usable. Looks like ill be running 44's instead.

 

[DK-Freestyle]

If you think those carbs are bad, you should see some of the rebuilds we do at our ski shop. Nothing a little wire wheel wont clean up though.

 

[#ZERO]

I dont need carbs, just was wondering what causes a diaphragm to melt like that.

Those diaphragms vibrate with every engine stroke and worn out from the debris inside which was caused by the salt water corrosion. The carbs should be completely disassembled and have all the fuel passages inspected & cleaned thoroughly. Also you might want to replace those valve body screws with stainless ones to prevent them from rusting again.

 

[kevbo]

Those dont look all that bad. Salt water is usually worse but fresh will do the same thing. Your story is all too common and the reason I never buy used carbs and cranks.

 

[LeftysRule22]

Your right, it seems every used carb i come across is crapped up somehow. I drilled out the screws and got to the jets, Im currently trying to get them out. One thing McMaster is good for - still have a bag of 48 stainless screws from when i replaced 2 in a carb a while back. Can you guys recommend some techniques/tools/chemicals for a backyard mechanic to clean these out properly? Im not sure how far I want to continue since rebuild kits, new n/s, springs, and jets are going to cost more than these are probably worth :1zhelp:

 

[waxhead]

take every part of rubber you can get out of them, then heat them up in the oven, when they are warm then drop them in to a crc, wd40 solution this will cool the carb and draw the cutting compound into the threads. let them sit for a while in the solution and try again.

 

[kevbo]

As peviously mentioned, a small wire brush on a Dermel will knock off the dried crud without hurting anything else. Just use slow speed and be careful.

 

[#ZERO]

I've been blasting them clean with fine mesh media after they're completely disassembled and re-dipping them in Alodine 1201 or Iridite 14-2 before painting with good results.

 

[BruceSki]

man zero, your stuff is always so meticulously clean. I'd have gave up and snagged another set of carbs off a running ski haha.

 

[LeftysRule22]

Wish I had the tools to pull that off lol. I wire brushed them out this afternoon, they look much better. I cant quite get down inside the n/s area. The only wire brush I had is the wheel, and the nylon cup doesnt do much. What about the passages as well, just carb cleaner? Since yall have conviced me to keep going I wanna get it right uppy_dog_eyes:

 

[WaveDemon]

I usually pull a wire out of a wire brush and use the wire with carb cleaner to clean out the fuel passages.

also with carbs, I make sure I set the screwdriver in the screw and shock the corrosion with a couple of taps from a hammer on the back of the screwdriver to get those fuel block screws out.

 

[LeftysRule22]

Yea, I discovered that using a clamp helps - One end on the fuel pump side, and the other end on the fuel block - little pressure to compress that rubber seal below it is just enough to relieve some pressure on the screws. Do carb kits come with the o-ring around the needle seat? Mine crumbled off, lol.

Thanks for the replies gents.

 

[QuickMick]

As peviously mentioned, a small wire brush on a Dermel will knock off the dried crud without hurting anything else. Just use slow speed and be careful.

Glass bead blast is what I use to clean dirty carbs. They come out looking pretty good inside.