1955 R112 drains fuel bowl

I have used a similar check valve on my hit and miss engines. What you call crack pressure is low enough to be compatible.

So I put a rebuild kit in the carb and all seems good now with the fuel bowl drainage. I had never said anything on prior replies as I wanted to resolve the issue first but it would be very difficult for the gas the run back out the fuel line due to the elevation of the inlet line. I think even with a siphon effect it would only be able to siphon a little bit.

I really think the issue was likely something internally leaking the fuel from the bowl down into the intake after it was shutoff. I did drain and refill the oil just in case as I had been fiddling with it for a few weeks on and off.

Thanks for everyones input.

Mike