Well dammit. This means the carbs have to come off for a rebuild. Float valves are stuck on 2/4 carbs on the CB500 and several firm whacks with a screwdriver didn’t loosen them.
On a plus side she ran perfect with a new battery, outside of leaking gas...
New gaskets and float valves/seats ordered. Just a shame I have to spend an afternoon to install $20 of parts.
Such is the life with old bikes though. It is why I bought a new one - it starts right up like magic when I press the button!