Gas leaking from both carbs

[drolston]

From:
Stromberg 97 Troubleshooting Help (carburetor-parts.com)
"After running the engine and warmed up, turn off and look down the carburetor to see if gas is dribbling from the venturi. If so, then the discharge check ball may be leaking, or a non vented gas cap is being used, or perhaps the fuel bowl vent is plugged off."
Seem unlikely that for both of your carbs the check ball or vents are bad, so boiling the alchohol in E10 gas is probably the cause. Your better experience with non-alchohol gas seems to confirm that. But sometimes E10 gas is all we can get.

Maybe check your float levels to the low side of the spec?
Maybe drop thermostats from 180 to 160 degrees?

Maybe put a phenolic spacer under the carbs to block heat transfer?

[69a]

Originally Posted by drolston

The Stromberg 97 instruction manual states 15/32 to 1/2"

My apologies. I stand corrected. Thank you.
Van pelt says 15/32" to 17/32" so effectively as close to 1/2" as you can get.

[Terry,OH]

From my experience, set the distance from the top of the float bowl without a gasket to the top of the float at the free end. Stromberg does suggest 15/32 +/- 1/32 which can be a bit low. Uncle Max uses 11/32 which can be a bit high but usually works. I have been using 13/32. Do check fuel pressure keep it under about 2-2.5 is good if your using the original style inlet needle and seat.

[flathead4rd]

I have a pressure regulator in my fuel line. It's set at 2 psi. Stromberg carbs don't like anything above that. I'm running three 97's on my flathead. If you don't have one I recommend you get one.

[alchemy]

Which brings up a question: where do you fellas get a low register pressure gauge now that Dickster isn’t supplying them anymore? Something that isn’t huge and ugly.