Scrappy
Legendary Knight
I rather suspect that it's most likely that I have unwittingly dislodged something given that it had never once had this problem before I took the tank off even though I didn't really touch anything and the only thing that could have been bumped accidentally was the air temperature sensor on the top of the airbox (it's a gen 2 motor and I don't believe the Gen1 had this?). Either that or, given how brittle the wires for the fuel level sender were, that the core of some other wire has broken. I will do some investigation and testing. If the worst comes to the worst I will simply do some substitution testing by swapping parts with my yellow Sprint.
Trapped breather pipe? - I always have to double check if I've raised the tank on my Street Triple, as its too easy to get one of the pipes kinked or trapped.