https://bingcarburetor.com/petcocks.html


The problem is, or was, the fuel tank bung. Silver solder in place.
Not now > http://www.bungking.com/20mm-petcock-bu ... CS4mC7wKH0
NOTE: the "long" version has been discontinued, but the short one is the one needed with Karcoma petcocks.
A cross over fuel line is easy with a couple of "T" fittings.
And just like that, voila... no more fighting the freakin' cross over tube fuel flood when removing the tank.