Carburetor Rebuilding Question

I am in the process of rebuilding my 8N MS carburetor. Everything is out. The drain cock gave me a little hassle where I had to use the drill. The plug is out but I don’t understand the diaphragm looking thing at the bottom of the hole. With the plug out, I put liquid in the bowl and nothing is coming out, and it should be. The carb has been soaking in cleaner and right now in vinegar, so it is pretty clean. Before I punch/drill this thing out, I like to have a consensus.
BTW, I thought that it was part of the plug, but the plug was not that deep.

No straight shot from the plug hole into carb bowl, rather the bowl has two ~1/8" holes that should enter into the area under the plug from the sides of plug hole.

NCmau,Yup clean the rust out of the two feed holes to the bottom drain plug that are plugged solid with rust.

Will do. Right now the carb is taking a bath in vinegar for couple of days and that is after 3 days in carb cleaner. The rust should be dissolved by then.

(quoted from post at 13:26:01 07/11/18) Will do. Right now the carb is taking a bath in vinegar for couple of days and that is after 3 days in carb cleaner. The rust should be dissolved by then.

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If that doesn't do it soak it in Evaporust for a couple of days. That stuff works.

FYI: Vinegar works to dissolve dirt and rust to an extent but works slow. It will also evaporate if not contained. Put carb halves in a coffee can, fill with vinegar, seal the lid on, let stand for weeks, months. Lacquer thinner works better than the carb cleaner they sell nowadays and so does plain old mineral spirits. Most 'snake-oil' products sold today are 99% mineral spirits. That Evapo-Rust product is just another snake oil product. Here's the MSDS sheet -no hazardous stuff BUT is water based. Guess what? That tells me it most likely is organic like vinegar. When a company doesn't list the ingredients in their product, that is a sure sign they are hiding something. It doesn't matter if chemicals are inert or not, if not listed, walk away. Some companies even try to say their product contains 'proprietary' ingredients/information and thus cannot be disclosed. Pure Bull Shoot. See that other port central on the bottom? That is also an overflow drain port. It was originally made with horsehair, but later sintered bronze. That means it is porous so needs to be soaked and cleaned well. Do not remove it, ditto with drain port/plug. The drain plug is a 1/8 NPT -National Pipe Taper thread. Only use identical part if replacing and don't try chasing treads with anything else.

Tim Daley(MI)
EVAPO RUST MSDS

Interesting! Thanks.

That Evapo-Rust product is just another snake oil product.

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No offense, but have you used it? I have. It works. I've used it on several rusted motorcycle gas tanks and a boat load of rusty nuts & bolts. Give it a little time and they come out looking brand new.

The key is to get all the crud off and down to the rust. Ethanol gas leaves a residue that needs to be cleaned off first. A mixture of hot water and Oxi-Clean takes care of it. Then the part is ready for rust removal.

No offense taken, but no need for me to use it. Also, I never said it doesn't work either. Just saying read labels, be skeptical, as there are many 'snake-oil' products out there. Most have a main ingredient like mineral spirits that does work well so no doubt their products work, eventually. When I spend my $$$ I like to get a good value, a good product I know is going to do the job. I buy in bulk as I use mineral spirits for many projects. If I'm out I just use a can of Kingsford Charcoal Lighter Fluid -same exact stuff. BTW what is the residue that ethanol leaves? It's alcohol and will evaporate when expose to the air. Gas will turn gummy when it gets old -that's why I use lacquer thinner to clean carbs with.

Respectfully
Tim Daley(MI)

Agreed. Be skeptical. There are a lot of snake oil products out there.

Mineral spirits is a great cleaner. I keep 5gal cans of it around. Not the weak paint thinner. Kingsford Charcoal Lighter Fluid is a true unsung hero - that stuff is great! It's works really well for removing adhesive residue among other things.

Back in the day I used gasoline for cleaning parts. It works really well, but had I known then what I know today.... :shock:

I don't know about the ethanol residue, though. That thick, orange sh!t does not evaporate. It takes a cleaner to remove. Nasty stuff.

(quoted from post at 20:31:56 07/11/18) No straight shot from the plug hole into carb bowl, rather the bowl has two ~1/8" holes that should enter into the area under the plug from the sides of plug hole.

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Sure thing JMOR! Finally after days the two lil’ holes showed up. They were totally covered with rust. With the help of a wire, I managed to fully clean them. I would have never known those holes were there. That got me more curious and found an excellent free manual. For the benefit of members that need more info than the N manual, just google “Free carburetor manuals” and practically you get a list to choose from of every carburetor made.