Dripping gas at carb- what is wrong with shutoff?

[avantey]

On my 1913 Stude I have had a problem with fuel dripping out the carb this spring. This is a very low mileage HPOF car that was fine until now. But we have had 10% ethanol in our NY gas for a few years.

After having read a few threads on ethanol and floats I looked up the float in the parts manual and sure enough, it is a ring style cork float. I bet it is soaked up now that the shellac is eaten by the ethanol. I will check on that.

My question is about the shutoff valve under the tank. I close it every time I stop but apparently it is not sealing off either. It is a brass quarter turn valve and I am guessing all brass inside. Could the ethanol have cleaned away the built up gunk and now it is getting bypass leakage around the ball shape in the quarter turn? The parts book list and illustrations do not show any rubber or gasket materials in the valve other than packing for where the handle exits the body. (I do get wet fingers when shutting it off so I know the packing is failing too. What is an ethanol resistant option for packing?)

Any thoughts on what to look for are appreciated. Thanks!-

[unimogjohn]

Bill, my shut off valve in the 28 developed a leak too. Turns out it was a split in the brass threads.

If I were you I would remove it from the tank and inspect it, and replace the packing while you are at it. That should fix it. You could have some debris between the needle and the seat.

As for the leaking carb. Yes I would check that cork float to see if it is starting to get fuel logged and slowly sinking. If yes, let it dry out and then coat it with Super Glue. The glue is not effected by the reformulated gas. Some folks coat their float with gas tank sealer, that works also.

[carbdoc]

Bill,

Your instincts about the carb float, the drain cock and the ethanol are basically right. Although you cork float was bound to fail eventually, the ethanol and other nasty gasoline additives accelerates the process. It may also be interrupting the seal between your needle and seat due to an elemental reaction which I contend that the ethanol has with bronze carburetor bodies; I am currently having this theory tested by a chemical researcher at North Carolina State University.

As to the drain cock : it may indeed be the "gunk" factor, but it is more likely the presence of grit on the valve's sealing surfaces transferred from upstream of the drain cock complements of our mutual friend, ethanol, which is an excellent cleaner but a poor motor fuel.

I would remove the valve (fun, I know, unless the tank is empty), disassemble it and clean and polish the sealing surface. Here at Old Carb Doctor, we use Mother's Mag and Aluminum Polish on all smooth brass surfaces if the part can't be tumble polished. Then repack your gland valve with some old-fashioned graphite-impregnated rope or ribbon packing. This may require a bit of internet searching, as “the good stuff” is no longer available through hardware stores (at least not in my area). Do NOT use Teflon packing (never seals) or the type of graphite packing which appears to be made from Silly Putty (modern gas dissolves it instantly). Look toward a supply place which sells parts for electric- and gas-driven water pumps; that is where I buy mine. Lubricate everything that moves with assembly grease (including the now-shiny sealing surfaces of the valve itself) during reassembly. All of this should slow the leaks -- both internal and external -- dramatically, if not stop the leaking entirely.

As to the carb: try using some Marine Formula Sta-Bil mixed into clean, fresh gas. It may be too late to help the float if it is bad, but it might help to neutralize the negative effects of the ethanol (don’t ask how – I’m no chemist).

In the "old days" (over a year ago), I might have suggested sending the carb here for restoration, and shipping the drain cock along with it. Unfortunately, I have suspended taking in restorations of bronze carburetors until this ethanol disaster (and whatever else comprises the toxic cocktail they are using to "poison" our gas) can be resolved or mitigated.

[avantey]

John and Jeff- Thank you for the replies and suggestions. I am beginning to really hate ethanol! I used the marine Stabil to winterize my cars and they fired right up which was encouraging. I expected the gas to have gone bad over four months.

Since we have tours and such oplanned for the Stude and summer is so short I amy wait unitl after the driving season to tackle the shutoff but I like your methodology Jeff. For packing I still have good graphite stuf from my Model A suppliers that I can try.

I had not thought of the gunk being moved downstream to the seat and needle but it makes sense. I did read here of the Super glue and airplane dope coating but all coatings seem to prefer a new, never touched gas cork for good adhesion. I will probably try to find a large enough piece of cork to make a new ring and coat that.

Again, THANK YOU for the help! Aren't old cars fun? (Yes, yes, yes) it's the modern stuff that interferes!

[carbdoc]

Bill,

You are welcome.

I tried to post the following info earleir, but I couldn't get the site to "take it".

Try Jelinek Cork for top-quality new cork blanks ("stoppers"): Jelinek Cork Group - Eco-friendly since 1855

And John,

Where can I buy Super Glue in quantities suficient to coat a large float (some used on fire engines are as large as 5"+ in diameter) without having to empty a half-dozen of those little tubes? I have heard of this technique before, and I am anxious to try it!

Jeff

[nickelroadster]

Carbdoc, the best place to get superglue (or cyanoacrylates as it should be called) would be a Hobby Shop that deals with model airplane supplies. Look for Pacer products, They should be on the internet also. You should have a choice of thick or thin (you need thin) and differing cure times and you can get fairly large bottles. Something else that you can get there and that also works well is fuelproof model airplane dope. Use clear and give it a couple of coats. This stuff is designed for almost totally alcohol fuel. One advantage to this is that it is much lighter than superglue. After all you want the float to "float".

[carbdoc]

Nickelroadster,

Thanks for the input. Is airplane dope similar to Testor's plastic model cement?

[nickelroadster]

Totally different product. Model airplane dope is the same as fuel proof dope used on vintage airplanes. The best place to find it is a hobby shop that caters to model airplane people. It is nothing like plastic airplane cement. lokk it up on the internet.

[avantey]

Jeff- I just looked at the Jelinek site and it is great! I can definitely find a cork blank there but I have a question- What kind of cork would you suggest? They have burl, natural, high and low density, and many other types. Even rubber materials in ring form. I think a natural block may be the way to go but I do not know if high density would be better for penetration prevention.

Any thoughts? They do have a tech assistance line and a section on floats and gasket use that I will probably call.

[Guest Al Brass]

Hi Bill,

There is a modern plastic that will replace the cork. It's light, easy to work and is not affected by modern fuels.

I have used aero gas tank sealer on cork and brass floats but not sure how it would go with ethanol, we've yet to face that problem down here.

Regards

Al

[avantey]

Al- You are lucky!! No ethanol? Maybe I'll move..... Seriously, I hope things are getting back to normal there after the quakes. Do old cars get lost in an event like that?

Now tell me more, always willing to learn! Is there a site to check it out concerning ethanol or to buy this material? Or at least a product name to search?

Thanks, Bill

[carbdoc]

Jeff- I just looked at the Jelinek site and it is great! I can definitely find a cork blank there but I have a question- What kind of cork would you suggest? They have burl, natural, high and low density, and many other types. Even rubber materials in ring form. I think a natural block may be the way to go but I do not know if high density would be better for penetration prevention.

Any thoughts? They do have a tech assistance line and a section on floats and gasket use that I will probably call.

Bill,

Your Studebaker's carb should use the same high-quality cork stopper, RL 42 NATS, which I use here at the shop for most anything other than the "size huge" float often required for fire engine carbs. Going from memory, RL 42 NATS is about 3" across at its smallest diameter. Remember that cork is actually shaved bark, so virtually any cork blank will be composed of relatively thin layers bonded together. Density is therefore not as important as uniformity of surface (the absence of "craters").

Since they are not that costly, I would suggest that you buy at least three corks so that you can have some spares "just in case".

[carbdoc]

Al- You are lucky!! No ethanol? Maybe I'll move..... Seriously, I hope things are getting back to normal there after the quakes. Do old cars get lost in an event like that?

Now tell me more, always willing to learn! Is there a site to check it out concerning ethanol or to buy this material? Or at least a product name to search?

Thanks, Bill

Bill,

Visit pure-gas.org/index.jsp to learn where you may be able to buy no-ethanol gas in your area. Simply click on your state's abbreviation at the bottom to go to the list.

But remember: ethanol isn't the only additive used in gasoline today which may be injurious to carburetors; it is simply the most prevalent.

[avantey]

Just an update- I dropped the bowl yesterday and removed the float. It was very light, not soaked up at all and after looking at it I realized someone had fiberglassed it! There are remnants of glass cloth and resin, all turned tan, but it was dry.

Now the bad part- as I handled it I squeezed too hard and the ring float is now four pieces!! I am gluing it back together with cyanoacrylite for now but will have to make a new one. Live and learn!!!

Also as I disassembled- the upper part of the bowl was dry and the wet area was all around the bottom. After getting it off, the brass bowl has a one inch hole in the bottom with a large nut to mount it and no apparent gasket. It is probably the only gasket on this carb, there was none at the top of the bowl. I am now thinking the float/needle is fine and the ethanol ate the gasket at the bottom of the bowl but I have to inspect the mount area more closely. But I still have an apparent bypass on the shutoff at the tank.

A work in progress!-

[carbdoc]

Bill,

Please don't waste your time trying to repair the old float; ethanol eats fiberglass as well. Now that I know that you have a "donut" float, you can use a hole saw to open the middle of a new cork blank to the correct diameter, then finish the height and the outside diameter. Don't try to do it the other way around.

There certainly needs to be a gasket at the bottom, and there may need to be one at the top as well -- and it/they may even need to be of a certain thickness to work properly! If you wish, e-mail some carb pictures and your phone number to me at jdreibus@yahoo.com and I will advise. Please put "Old Carb Doctor" in the subject line.

To test the needle and seat: when your new float is made and installed, turn the carburetor upside down and apply vacuum to the fuel inlet. Any air leakage whatsoever usually indicates a leaking needle and seat.

Jeff

[avantey]

Well I did finish gluing up the old float. It looks and feels pretty solid and I may try reinstalling it for now. Or it may just become a good pattern for a new copy and never get put back in.

I ordered two blanks from Jelinek last nite and they will be here in 10-14 days. That is a long time in our short summers and then I have to carve the new one which will take time- the area for mounting a screwed on hinge piece looks a little tricky to do. By then we are in the middle/late August and we are on tour the weekend after Labor Day. That is why I may try to use it again but we will see how long it takes to get the new cork delivered.

I just can't understand why it takes up to 10 days to pull an order when you have 14000 pieces in stock and how Toronto is that far from upstate NY. We are just across a big pond called Lake Ontario! I can drive there in four hours......

Jeff- thanks for all your help-

[carbdoc]

Bill,

You are welcome.

Jeff

[avantey]

One more question! I went to the local parts store and they had no gasket material for ethanol gas. I have natural cork but too thick and rubberized cork. I believe the Ethdamitall will attack the rubber. Will the black paper material work? If I coat it with cyanoacrylite? I have it at .030" which is about what the remnants of the old gasket measure.

Thanks-

[nickelroadster]

Red fiber gaskets which will work fine are available in many places. If nothing else try Restoration Supply in Escondito California. They have many different sizes. Pay attention to Carbdoc and do not try to reuse your old float. The thing probably weighs way to much now. You might even try to get a brass replacement at Tractor Supply as they have many different sizes of donut shaped carburetor floats.

Edited July 27, 2011 by nickelroadster
addition (see edit history)

[carbdoc]

Bill,

Nickelroadster is right about Restoration Supply Co. as a source for the red fiber washers.

For larger gaskets, I cut them from Fel-Pro #3157 (1/32" x 10" x 26") and #3187 (1/16" x 10" x 26"). Use the 1/16" material for flange gaskets (to intake), and the 1/32" stuff for most everything else. The grey material is described by Fel-Pro as "rubber fiber", but it is very easy to punch and to cut and it stands up to the gasohol very well (at least so far).

[avantey]

Just an update- I did glue the old float back together and then coated it with two coats of cyano. Put it, driven the car twice and it seems fine. The new blanks will be here maybe next week but I couldn't wait to drive the Stude again!

I also bought the thinner suggested gasket matl and it sort of worked. The needle at the carb bottom is now wet but doesn't drip. I guess it evaporates fast enough to counter the drip. I also picked up a wet condition at the line fitting when I reassembled, again not enough to drip. I figure when I install the new float I will fix these issues by making another gasket and re-flaring the line.

But for now we are cruisin- as much as a 1913 can cruise anyways! And I only glued three fingers together to get here!!

[carbdoc]

Bill,

Before re-flaring the fuel line, try some Permatex High Performance Thread Sealant (teflon thread paste). Put just a little bit on the threads, as well as between the flare and the nut (just put a tiny dap on the flare, then spin the nut on it); that will usually stop 'em from leaking.

But while we are on the subject, NEVER use teflon thread tape on anything automotive!

Jeff