Carburetor gushing out of bowl

[loch]

Hey Everyone,

1932 VL with an Linkert M31

Been a while since I've had a problem completely stump me. This began without warning the last time I was going out for a ride. I had a similar situation on the Panhead. But that started when I was on the road. A quick adjustment of the float was all that was required. This time it occurred when the machine was on its side stand and persisted when the placed on the center stand (checking to see if the float was stuck against the side of the bowl).

This is what I've done so far: 1. disassembled the float bowl from the carburetor body. Test the valve seat by turning the bowl upside down to so the weight of the float closed it. Could not blow air through the fuel intake. Pushed up on the float to open the valve while keeping air pressure against the valve. Could hear air escaping through the valve. Let the float back down and no air. Did this several times to verify valve wasn't blocked or just had a worn seat. 2. Place the bowl in a large bowl and filled it with water to witness the float actually floating. It does float and though a few bubbles emerged from near the screw (the float is brass) they stopped. After several hours the float was still fully floating.

The measurement of the float from the edge of the bowl is still spot on, at 1/4" from the lip of the bowl.

So what could this be? What other tests can I do?

Barring any other suggestions I could adjust the float height to put more pressure on the valve, I could replace the valve. The latter I'm not a fan of since it seems to seal. Throwing parts at the problem without cause is never a good idea.

Thanks!
Loch

[T. Cotten]

You don't test the valve by blowing on it Loch,

You must suck upon it, and hope you will feel a little pop when you pull your tongue off.

Then index the bowl upon the body and invert the entire carb, and repeat the suck test to be certain the float is not rubbing the bowl or bowlstem.

Excessive play on the pivot pin increases the probability of hanging up, but brass floats don't float anyway:

JARTEST3.jpg

...Cotten

[dukekleman]

Loch,

Have you reinstalled the carburetor assembly after your test?

[loch]

but brass floats don't float anyway

So let's have a lesson in physics kids.

1. Brass floats do float.

2. Brass floats filled with gasoline float in fresh water.

3. Brass floats filled with gasoline don't float in gasoline.

Why is this? It should be obvious. Gasoline is lighter than water.

I will spare everyone the diatribe of the principles of buoyancy.

I realized all of this before reading this post. By the way, thanks T. for your response! And the awesome imagery.

So, after the episode this morning, of once again watching the fuel come rushing out of the overflow port I sunk into a definite funk close to depression. But I put up the question to all of you because I knew I'd get some insight. And then I pulled up my figurative bootstraps and went out into the gloomy overcast day, complete with cold breeze, and began doing the needful.

Upon disassembly of the carburetor I decided to check all of the things I didn't check before. I sucked as T suggested here (thank's again for the input!). And then I pulled the float off of the lever. Flipped it over and gave it a couple shakes with the hole at it's lowest point. And guess what? Out came gasoline. And I knew instantly what caused the issue. And why when I did the test in fresh water the float remain on the surface. So I shook and shook and shook and shook. And with each shake my spirits lifted, and I'm not embellishing when I say the clouds parted and the sun shined down upon the land. All was well again. But don't stop reading here.

How did the gasoline get in there? I was going to immerse the float in fresh water again to see if I could see a pinhole. And then I looked at the screw used to hold it to the lever. Yup, don't need to do that test. The washer that is supposed go between the lever and the float, to seal the hole so it doesn't fill with gasoline, was resting against the lock washer. Which means it was positioned against the lock washer and the lever - doing absolutely no good whatsoever. Ah! YOU DUMMY! Did I do that? Who put this thing together anyway? Remember folks if you want to seal something, the sealing device needs to go closest to the thing it's supposed to seal. Not on the other side of something else. I didn't do that. Someone else must have been mucking about with the Sergeant when I wasn't looking.

One last note: I prefer the brass float. A lot of kits come with the fiber floats. I think you have to hunt around for the ones with brass floats. So if you don't want to experience the image in T's reply and have a sinking brass float that accidentally filled with fuel - go with the fiber. The fiber floats aren't hollow. And as T points out, always ensure there's no chance the float can get stuck against the side of the bowl. This has happened to me because I didn't pay attention to the position of the float in the bowl when tightening the screw. This can happen with either fiber or brass float.

The Sergeant is once again running on the first kick - and not spewing fuel everywhere.

Thanks Everyone!
Loch

[T. Cotten]

Speaking of buoyancy, Loch,..

Even without a hole in it,
BRASHOLE.jpg BRASSFLASK.jpg BRASHOL2.jpg

A brass boatanchor is three or more times as heavy as a proper float. And it has an increased volume in an attempt to make it float.

To get the same 5/8" fuel level in the bowl, the fat float must be set as low as possible, 3/8" to .410", where its nearly out of travel to open the valve fully, and it occupies the reserve volume needed for acceleration and normal performance.

FUELVOL3.JPG
(Your model only has the volume between the top two lines available, and the brass would have to sit at the middle or even lower.)

Its extra mass leads to not only premature wear of the lever and pivot,

FNGRWRX.jpg

But a sluggish cyclic response to demand. There goes mileage.

....Cotten
PS: L&L never made a brass Model M float.

[BigLakeBob]

I don't use brass floats in my linkerts, but if they are so bad why do they work in a bendix just fine?

[T. Cotten]

I don't use brass floats in my linkerts, but if they are so bad why do they work in a bendix just fine?

Its been decades since I touched any Bendices, Bob,

But didn't they need an assist spring on the pivot, to just help the float float?

(When all else fails, add another variable!)

...Cotten
PS: Just for more fun, remember Kokesh boatanchors?

Kokesh instructions.jpg