Cleaning plugged carb drain

MarkB_MI

Well-known Member
Location
Motown USA
Marvel-Schebler carburetors (and I assume many other updraft carbs) have a drain that's blocked with a sintered bronze plug. The plug is supposed to let excess gas drain out while keeping dirt from being sucked in. On my carb, the plug is blocked, so nothing drains out. I assume fifty-three years of gunk eventually "plugged" the plug. Has anyone successfully opened a plugged drain, short of drilling it out? I tried soaking it in MEK (methyl-ethyl-ketone) with no success.
 
Sandblasting the plug clean usually works for "crud".
I'm not sure what model carb you're talking about, but they
are usually staked in and can be replaced without drilling.

There are also screw in versions available if you want to drill
and tap the bottom of the carb to accept them.

On one of my own, I converted it from the sintered strainer back
to the old fiber filter with a washer staked to hold it like a TSX-33.
Purpose still served.
 
The best way is to soak the float bowl in the no longer available (thanks, EPA) carburetor cleaner that worked.

I have no idea if the stuff that is available these days works but I doubt it.

You might try soaking it in Gunk carburetor cleaner if it is still available.

Dean
 
You can buy the sintered bronze weep plug from Roberts carb or measure yours and order one from McMasters. When you drop the bottom off the carb you will see a hole in the casting on the inside to pop it out. Seems like I used a 3'32 pin punch but I've slept since then. The new one will tap right in and stay, just use a larger pin punch. Seems like the plug is about $5.
 
Thanks M-Man. I just assumed that plug wasn't available. It's about 15 bucks from Roberts. Looks like Marvel-Schebler P/N 95-78 is used on just about all M-S carbs. I didn't have any luck finding one on McMaster-Carr; do you have any idea what they might be called? They have "<a href="https://www.mcmaster.com/#vent-plugs/=19v2xtr">breather vents</a>" which should work, but I'd have to tap the carb.
 
They are sintered bronze filter discs. Looks like Mcmasters only has them in stainless now a day's. Google shows other sources. I bought several from Roberts years ago at a much lower cost but like everything else prices do go up. Guess my next batch will hurt more. lol
 
Thanks again, M-Man. The stainless discs only come in a few sizes; I don't think they'll fit my carb as I think the hole is about 3/8" diameter. Looks like the M-S replacement from Roberts will be the way to go.
 

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