carb leaking gas, what did I do wrong?

51 MERC-CT said:
Pull the float to determine if it has gas in it.
Click to expand...

Ok, that will be my next task.

EDIT:

Ah ha! I just removed the carb off the car and pulled out the float and gave it a shake... sure enough, it's full of gas! I wiped it dry and I can see gas seep out immediately... I guess a new float is in order!

At least I now know what the culprit is. (probably could've found it a lot sooner but I'm still learning so always afraid of taking things apart and risk making it worse, or not being able to put it back together correctly.)

Thanks everyone!
 
Last edited:
Jason,

I know MAX and I know he'll do you right. By the way do not submerge the float
in hot water....luke warm is sufficient....hats off to '51 MERC -CT
J B Weld is good stuff but in this situation I would not do it.


Charlie ny
 
Last edited:
Charlie ny said:
Jason,

I know MAX and I know he'll do you right. By the way do not submerge the float
in hot water....luke warm is sufficient....hats off to '51 MERC -CT
J B Weld is good stuff but in this situation I would not do it.


Charlie ny
Click to expand...

Although MAX may do him right, to get him to the car show would it work to:

Do the water test to locate the hole and attempt to solder it? But use warm water NOT hot as to not cause the fuel inside to expand and Explode!

Once the pin hole is located, drill it out with the tiniest drill bit you got to drain the fuel before soldering.

Re check again after repair to ensure its sealed.
 
If you can determine the area of the crack or pinhole, it can be fixed buy drilling appox. 3/32" holes to let the gas drain and then set aside in a warm area to allow the gas to evaporate. Occasional use of compressed air will help
(don't apply air pressure to the float).
You can tell if the evaporation is sufficient by smelling it.
Then it's just a matter of soldering to seal.
Have done several in this manner with success.
 
Last edited:
Just tuned in to all of this; been off doing taxes preparing for my CPA (Cleaning, Pressing and Alterations!) for nearly a week...
New float, pin and gaskets headed for Texas in 15 minutes.
Did I say I'm sorry.
 
uncle max said:
Just tuned in to all of this; been off doing taxes preparing for my CPA (Cleaning, Pressing and Alterations!) for nearly a week...
New float, pin and gaskets headed for Texas in 15 minutes.
Did I say I'm sorry.
Click to expand...


Is THIS place GREAT.....or what? DD
 
This truly is an awesome forum! With all the help and additional searches through previous posts, I feel like I got a solid crash course in carburetors!

As Max mentioned, he reached out and will be sending a new float, much appreciated!

As for the car show this weekend, I followed Will D's instructions and drained the gas through tiny drilled holes and then soldered them up. Then did the hot water test and no bubbles! Took a test drive and it runs fine (I think I just need to adjust the idle screws to get a smoother ride). I don’t trust my soldering skills 100% so this is definitely a temporary solution until Max’s new float arrives.

Thank you so much to everyone!
 
And ladies and gentlemen, this is why you use the incredibly awesome vendors who populate this forum.

Over the last dozen years I've got experience with Uncle Max taking a very stinky leaking filthy carb and making it showroom for my '35.

And Charlie has his fingerprints all over my '36 Phaeton (trans, rear, carb, steering, FP, and more).

They are very high on the list of people who get my business so I can get back to driving and smiling!

Their messages here are totally typical of how they handle things.
 
Last edited:
moefuzz said:
.Your fuel pump is mechanical or electric?

The original mechanical fuel pump on top of your intake may be pushing to much pressure.

Your carb is not designed to handle over pressure for very long and can be over
powered by the fuel pump in a matter of seconds, minutes or hours...
...until it can't physically hold back the excess pressure anymore and it will finally give up.


Quick and easy fix=


You can add an extra gasket (or 2) underneath the fuel pump stand at the intake,

this has the effect of shortening the fuel pump pushrod and will decrease fuel pump pressure somewhat.

The longer the fuel pump pushrod "appears" in relation to the physical height to were it is mounted dictates fuel pressure.


So Hypothetically, if you (don't do it!) were to grind the fuel pump push rod a 1/16th or an 1/8th inch, it would have a shorter stroke and would not push the pump as far or as hard.

Adding an extra gasket under the fuel pump stand at the intake
has the effect of shortening the rod and lowering fuel pump pressure.
You can add one or 2 extra gaskets and experiment.

Don't ever grind the fuel pump pushrod to lower fuel pressure or push or stroke at the fuel pump as this is not easily reversible and over time the mechanical fuel pump looses some of it's pressure at which point you can always pull one of the extra gaskets out.

Also, there are 2 different fuel pump pushrods lengths depending on your intake.

Check that yours is close to the below specs dependent upon aluminum or cast intake manifold.

52-9400-A Push Rod - Fuel Pump (V8-60hp) - Alum. Intake (5.625")

52-9400-B Push Rod - Fuel Pump (V8-60hp) - Cast Iron (6.375")



Back in the old days gaskets were relatively thick,
now a days gaskets are less then paper thin so you may have
inadvertently/unknowingly "adjusted" the fuel pump pressure
upwards by installing a paper thin gasket and you wouldn't
even know it until the needle and seat (float) are
over powered and flooding happens..


Extra gaskets are cheap,

...Cheap enough to buy a couple and still have money for your morning donut


457280




.
Click to expand...


Read post #5.

Sal
 
float level or pump pressure out of curiosity did you run the eng around 1500 rpm have seen fuel pump pressure climb dramatically above 1000 rpm
 
You must log in or register to reply here.
Back
Top