Carb float problem

[6lucky13]

My carburetor problem started a few weeks ago. My car began to stall on stopping…I adjusted the needle valves and checked the idle rpm not thinking it was a float problem. Yesterday I took the car out and the carb flooded…luckily I smelled gas and returned home before the engine got hot. I’m now guessing it is a stuck float valve.
What is the best method to adjust the float valve…the gauge method (which I used before) or ?
Second related questions…what would cause a float to stick? I have been using Sta-Bil (regular and, for the past year, marine formula) in the gas. Can this cause a problem by gumming up the works? Should I return to using MMO in the gas? Don’t want this to happen again!
Thanks for your thoughts.
Kerry

[6lucky13]

Carb is a Stromberg 97 on a '37 engine...

[flatjack9]

Forget all the additive crap and use non-ethanol fuel.

[scicala]

I wouldn't just say that it's a stuck float necessarily. Best to take off the top and see what's going on, and go from there.

Sal

[uncle max]

There are just a few things that cause your problem...
Fuel pressure too high... 2-1/2 psi is just right.
Float level too high... Set the free end 9/32" down from the gasket surface.
Stuck needle in fuel inlet... Clean and check for debris or replace if needed.
Possible pinhole developed in float... Submerge in hot water and look for escaping bubbles. Make sure tang is not hitting bowl when replacing.

[G.M.]

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I was on a 1 hour trip to a car show a number of years ago when my 39
flooded out. It had a Stromberg so I pulled the top off and started it. The
float had a small stress crack on the top and sunk. I pulled the float and it
was loaded with gas and as it cooled the crack closed and the gas wouldn't
come out I held it with pliers behind the exhaust pipe of a modern car and
it boiled the gas out. I rebent the arms on the float and put it in upside down
and went on to the show running good. I drove it a few weeks and decided I
better put a new float in before I forgot about it. A lot of floats in the carbs
and fuel tanks split because they are drawn in one shot and work harden.
They should have been made in two draws annealing between them. G.M.

[FlatheadTed]

Thats pretty innovative GM .Ted

[6lucky13]

I checked the float in both cold and hot water...no evidence of a leak. The ball valve seemed to operate correctly and the float was set as descibed by Uncle Max. I compared the accelerator pump from the problem carb with another one I had and saw a diffecence between the two. Is there a ball valve or check valve at the end of the pump? The pump on the right is from the problem carb. Might be difficult to see but the one on the right has nothing over the hole. Could this be the cause of flooding? The gas was pouring out through the pump top of the carb plate.

Kerry

[JM 35 Sedan]

I would suggest checking the accelerator pump check valve for proper function, Stromberg part # 9573k. This check valve is under the center bowl plug and allows the accelerator pump (as shown in your last two pictures) to suck gas in but not back out into the float bowl.

http://www.stromberg-97.com/#

If you can confirm that the accelerator pump check valve is not crudded up and maybe stuck open, then why not replace the accelerator pump on the right side of your picture with the one on the left side, assuming the one on the left is the correct part for use in a 97

[G.M.]

Originally Posted by 6lucky13

I checked the float in both cold and hot water...no evidence of a leak. The ball valve seemed to operate correctly and the float was set as descibed by Uncle Max. I compared the accelerator pump from the problem carb with another one I had and saw a diffecence between the two. Is there a ball valve or check valve at the end of the pump? The pump on the right is from the problem carb. Might be difficult to see but the one on the right has nothing over the hole. Could this be the cause of flooding? The gas was pouring out through the pump top of the carb plate.

Kerry

You can run the Strom with the top of the carb removed. That way
you can watch the function of the needle valve. A needle valve usually
shows movement of the float as it don't respond to level changes like
the double ball valve. The double ball type acts so fast you don't see
a change of fuel level in the bowl. Just be careful and have a fire ext.
handy. I have done this 1oo's of times and never had a problem. G.M.

[6lucky13]

So...I checked the accelerator pump check valve for proper function, as suggested by JM 35 Sedan. Was fine. I, therefore, replace the accelerator pump with the one on the left side of my picture (again suggested by JM 35 Sedan). And...problem solved! The '36 Cabriolet is back on the road!

Thanks for all the suggestions. Hope this is helpful to someone. It's not always a float problem!

Kerry