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1922 Buick running a Marvell carburetor


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I’m having an issue with flooding. We have changed the float and she still floods. I’m going to change the key again ( I think the one I put it was poorly fitting ). Should I ( or can it be done ) lap the jet in to the seat. 
OR is there something I’m missing. 
I’m told it’s just another challenge NOT a problem.  
it’s the only thing holding me up to get on the road. 
Thank you in advance. David Marshall 

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David,

Are you using a hard tip or a neoprene tip needle?  

If you want to lap a hard tip, use a tooth pick to apply just a spot of fine valve grinding compound on the needle bevel.  Use a piece of tubing and tape to secure the needle to the tubing.  Use a push and slight turn motion on the needle in the seat.  Do not do rotary motion.  Think about trying to create a cross hatch pattern on the tapered sides of the needle point.  Check it when you are done by holding the needle and seat closed and blowing or sucking on the fuel inlet.  Use a Q tip to clean out the grinding paste.     

I am under the assumption that you are gravity fed from a vacuum tank and not using a fuel pump.

Hugh      

 

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No joke. Whitening toothpaste has an ingredient that is hard enough to remove varnish and rust from the seat, but not hard enough to remove any metal from the seat. Regular toothpaste doesn't have this ingredient. Whatever the ingredient is, it's hard enough for coffee stains from your teeth but not hard enough to remove enamel. So emery powder is too hard, would you use it on your teeth?

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  • 3 weeks later...

Thank you everyone for the advice. UPDATE My mechanic has set the float to 9/16's ( not show how to explain this but from the top of the carby bowl ). We've lapped the needle in again and AGAIN it flooded.  The float has been coated in modellers "dope" to ensure it isn't absorbing the fuel.    I'm getting really frustrated and each time we think we have it, it floods again. 

I have ordered a new float from the restoration supply co nearly 8 weeks ago but I'm still waiting for it.   I'm guessing Covid19 is to blame.

Can anyone suggest anything I'm perhaps missing please.

Thank you everyone for the advise so far..  Regards David 

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Try removing the vacuum line that runs from the intake manifold to the vacuum tank  and plug the manifold port. Then clean the plugs and give it a start.

 

The lid of the vacuum tank has 2 small needles that allow fuel to enter the inner canister and/or block off the manifold vacuum when fuel isn't needed. If the needle is stuck (even a little bit) it will allow the vacuum tank to fill with fuel and not vent to atmosphere when full. Fuel will be sucked into the intake manifold, flooding the engine and stalling it.  Or the float in the vacuum tank could be full of fuel or sticking.

 

Good Luck

Edited by wmsue (see edit history)
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Use a rubber hose and low air pressure to see if you can locate where the leak is coming from.   Or go the opposite and use water with pressure from the garden hose on the fuel connection.  You may be able to get a replacement carburetor or bowl on Ebay or from Carb King.   

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Just my three cents worth of info, check to make sure (if you had the top off of the vacuum tank) that your gasket matches up with all eight screw holes and the ninth hole is not plugged - the extra ninth hole in the gasket fits over the breather tube protruding up from the tank and must be clear of debris, other thought is check your float in the vacuum tank - it cant have any holes or it will fill with gas and not work properly, make sure the float guide is seated in the center of the flapper valve at the bottom of the tank  Jim 23-6-48 Opera Coupe

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Even if the vacuum tank doesn't work, you can still add about a pint of gas to it, enough to start the car and let it idle for a minute or 2. Take off the small plug at the top of the vacuum tank, and fill the tank with a tiny funnel (I use the one that comes with a gift box of Jagermeister, for filling the hip flask, lucky for you it's Christmas).

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Lots of good advice here.........it doesn’t take much dirt to make the carb leak.

 

You mention the float has dope......so my guess is your running a cork float. Dope and sealer can make a float heavy and not push on the needle and seat well. Also, a float can bind on the hinge or drag on the side of the bowl. The tank has very little head pressure. So the carb will not leak if correctly set up. Problem is a 100 year old carb has a lot of chances to have been messed with in ways difficult to see or figure out. Don’t give up. Also understand that modern fuel is less dense and has a lower specific gravity than the old fuel.......this mean it doesn’t push as hard to close the needle because of physics. You need everything just about perfect for it to seal. I had a perfectly clean system on my 17 and all was fine till I stopped at a filling station and got dirty gas..."so then I had to install a filter in the system......it stopped leaking after that. It needs to be almost perfectly clean fuel or the carb will puke. My bet is a new float will solve your issues. I long ago gave up on cork..........to many times I had new floats absorb gas and partially sink. I only use brass for them for the last forty years..........problem solved. I go to tractor supply and look over their tractor floats and buy a couple of them that are close and start from there. They are reasonably priced. You don’t mention if it leaks while running, or if the car is flooding and running rich while driving. Your close to fixing it....don’t let it bother you, everyone here know what they are doing because they have taken theirs apart fifty times also........been there, done that. 

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10 minutes ago, edinmass said:

I only use brass for them for the last forty years..........problem solved. I go to tractor supply and look over their tractor floats and buy a couple of them that are close and start from there. They are reasonably priced. 

Do you have some online pointers to brass floats that might work with Marvels? How did you affix the float to the old arm? Do you find that the range of adjustment is plenty with a brass float?

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10 minutes ago, drovak said:

Do you have some online pointers to brass floats that might work with Marvels? How did you affix the float to the old arm? Do you find that the range of adjustment is plenty with a brass float?


 

Never done it on a Marvel. You have to become your own fabricator and engineering department. You can also buy synthetic float material and sculpt it with a hot wire to cut it into shape. Others have done it this way......me, I’m a dinosaur, I like brass. Photos would help.....let’s see what your working with.

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15 minutes ago, edinmass said:

I’m a dinosaur, I like brass. Photos would help.....let’s see what your working with.

I like brass as well. I've got a '31 Series 80 with the original carburetor. I've got a new float covered in Red-Kote, which seems to be working okay, but would like to consider swapping it for brass.

PXL_20201030_043251429.jpg

PXL_20201030_183944319.jpg

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Red Kote is a new one for me. Using gas tank sealer has been popular the last twenty years. If available back forty years ago, I’m sure I would have tried cork and a sealer. As long as the sealer isn’t too heavy, it works fine. Notice in the above photo how close the float is to the walls of the bowl. Many replacement and reproduction floats have very poor quality control and will often drag or stick to the side wall. Today too many people try and run an electric pump on a vacuum tank car.........a situation that begs for leaks and fires. It should never be done. I have heard good things about the synthetic float material. Another problem is generic needle and seats binding. I will usually lap in any factory needle I can get my hands on. I usually use assorted compound used in polishing shops that is available from Amazon. Less aggressive and easier to work with. 

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Ed:

I agree with the above having redone my 1925 Buick Marvel Carb floats with Nitrophyl materials. Cork coated as the above photos show make it much heavier. In many cases the coating of airplane "Dope" is much thinner and did not impact the weight much.

DSCF2638.thumb.JPG.2ab073d6e98e8ccb94daadbcbcc7010e.JPG New nitrophyl float on the right.

When the previous owner of my 1925 Master tried to redo the gas gage float this is what he did.

DSCF5824.thumb.JPG.0e3e7d01621d35cf6af17a4290c9c149.JPG Coated a larger cork and held it on with a NM wire cable staple. It weighed 3X as much as what the original cork example on the left. It sank like a stone!

DSCF5835.thumb.JPG.70b87f0e3eadb5f5456cc4253a387f75.JPG  DSCF5839.thumb.JPG.220905a4ddf655defbbbc08d8cbf294a.JPG

 The nitrophyl replacement I used. Snyders Ford parts. Only a couple of dollars and matched the original size.

 

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1 hour ago, dibarlaw said:

Ed:

I agree with the above having redone my 1925 Buick Marvel Carb floats with Nitrophyl materials. Cork coated as the above photos show make it much heavier. In many cases the coating of airplane "Dope" is much thinner and did not impact the weight much.

DSCF2638.thumb.JPG.2ab073d6e98e8ccb94daadbcbcc7010e.JPG New nitrophyl float on the right.

When the previous owner of my 1925 Master tried to redo the gas gage float this is what he did.

DSCF5824.thumb.JPG.0e3e7d01621d35cf6af17a4290c9c149.JPG Coated a larger cork and held it on with a NM wire cable staple. It weighed 3X as much as what the original cork example on the left. It sank like a stone!

DSCF5835.thumb.JPG.70b87f0e3eadb5f5456cc4253a387f75.JPG  DSCF5839.thumb.JPG.220905a4ddf655defbbbc08d8cbf294a.JPG

 The nitrophyl replacement I used. Snyders Ford parts. Only a couple of dollars and matched the original size.

 

 

!00% Agree with Larry D and did the exact same just this summer to my 1923 Marvel  Back to running perfect.

 

Watch for the float rubbing / hanging up on the wall of the bowl.

 

The whole float system takes a beating on a trailer ride when the bowl is dry and the float and pin have nothing to dampen the ride.

 

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1 hour ago, jscheib said:

The whole float system takes a beating on a trailer ride when the bowl is dry and the float and pin have nothing to dampen the ride.

 

 

Brian, As they say, Buicks were meant for driving, as you know.

 

John  


John

 

Believe you were around for part of my 1485 mile road trip around Lake Michigan.  My 1923 Buick never missed a beat. 
 

I do own a trailer for my 1911. 

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