an inch can make a difference
I had the petcock moved to the rear of my tank thinking that would solve being able to use all the fuel in the tank.
It did - but there is no reserve, riding paranoia set in at the thought of being stranded, constantly topping up with gas just in case, calculating just how many miles I can get out of a litre can be a little tiresome.
So experimenting, I extended the tube on the petcock. Had to lose the filter due to fitment, but I'd installed an inline filter on the petrol pipe line anyway.
The extra inch gives me a litre of fuel on reserve, or 8-9 miles to find a gas station. Phew.