Carb is weeping gas at top cover screws

[Mike_B]

So, my fresh carb is weeping gas at the top cover screws making the top cover wet with raw fuel. Is this a sign of the float set wrong? This happens overnight with the engine not running. I didn't put any gasket sealer on the paper gasket...should I have?

Thanks in advance,

Mike B
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Mike B
1953 M38A1 Brush Truck
1952 M38
1951 M100 Trailer

[wesk]

If the contact surfaces are in good shape you should never need to use a sealer on carb gaskets.

If you tell us which jeep your carb is on it will help with an answer.

I usually suggest to each of our members that you go to your profile page and add a signature element to all of your posts that includes at least your jeep's model number and your first name. Then the model of jeep referred to in your posts will always be obvious.

If you have an m38 then it is possible that you have forgotten the correct thick insulating gasket at the base of the carb to stop heat transfer from the intake/exhaust manifold which will cause perculation of the gas in the bowl after shut down.

If you have your bowl vent plugged this seaping can also happen.
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Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100

Mjeeps photo album: http://www.willysmjeeps.com/v2/modules.php?set_albumName=Wes-Knettle&op=modload&name=gallery&file=index&include=view_album.php

[Mike_B]

I fixed my signature...I had the info there but had double spaced it below my name and it didn't show...single spaced it and there it is! Thanks.

1953 M38A1...the carb is a YS-950.

It really looks like the gas is coming up the screw threads as the entire top is damp with fuel.
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Mike B
1953 M38A1 Brush Truck
1952 M38
1951 M100 Trailer

[wesk]

That leaves plugged vent and improper float setting.

If the leaking occurred during operation then you could suspect fuel pump pressure high.
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Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100

Mjeeps photo album: http://www.willysmjeeps.com/v2/modules.php?set_albumName=Wes-Knettle&op=modload&name=gallery&file=index&include=view_album.php

[Mike_B]

Thanks Wes, I'll look at both while I'm waiting for my starter motor to get rebuilt.
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Mike B
1953 M38A1 Brush Truck
1952 M38
1951 M100 Trailer

[Mike_B]

Ok, so I checked the vent and it's clear, it's piped from the top of the carb to the air intake as shown on page 70 ORD-9 SNL G-758.

I took the top of the carb off and adjusted the float again using a 1/4" drill bit as a gauge. Ran the engine for 30 min and called it good. Came out the next day and the top of the carb is all wet again. This time I noticed the carb intake right at the choke plate was wet with raw gas, but not the section of pipe the vent is connected to.

My question is when adjusting the float do you push down on the needle seat valve spring to set the height or not? I'm wondering if there isn't enough spring pressure to overcome the pump pressure. This is the first carb I've done that hase a spring at the needle valve.

I'll check the pump pressure later today, but since the pumps been there for 30 years I find it hard to believe it's putting out to much pressure.

Thoughts?

Thanks,

Mike B
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Mike B
1953 M38A1 Brush Truck
1952 M38
1951 M100 Trailer

[wesk]

No the float level is set with the float tab resting against the needle not with hand pressure pushing the needle in against the spring.
_________________
Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100

Mjeeps photo album: http://www.willysmjeeps.com/v2/modules.php?set_albumName=Wes-Knettle&op=modload&name=gallery&file=index&include=view_album.php

[Mike_B]

Thanks Wes, that's the way I have it set.

I believe the problem was I had the temporary fuel tank attached to the top of the grille guard which had it higher than the top of the carb allowing it to siphon into the bowl overnight. I lowered the tank and the problem went away. For some reason the needle seat must not close off 100% allowing a small amount of gas to seep by...this condition would not happen normally as the tanks below the carb.

Mike B
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Mike B
1953 M38A1 Brush Truck
1952 M38
1951 M100 Trailer