Some older bikes, like my '99 Ducati Monster, don't have a petcock. It has a low fuel light that first failed in around 2002, and for which that part that fails (the in-tank float switch) stopped being available in about 2015 or so. No petcock _or_ warning light. (And that trip where the speedo cable fails so I couldn't even use thew trip meter to estimate fuel requirements was a fun one...)
Can you find someone who can adapt a float switch from a different bike? It seems like a very useful thing to have, even if it's not the original factory part.
I've just gotten used to it. I'm fairly reliable about always resetting the trip meter when I fill it up (and always fill it to full). I know it'll get 200km easy, maybe only 180 if I'm having _way_ too much fun. That's always about time I want to stop and stretch my legs anyway. It doesn't bother me enough to "solve the problem".
