IT will start with throttle advanced and stall when shifted back into neutral.
It will not start in neutral, but push the button on the throttle lever and move the throttle forward it will start and run fine.
To get it in gear ( Forward) I need to quickly pull throttle back into neutral and...
IF the fuel pump is electric rather than mechanical it would be perhaps energized via the ECM and a relay.
I do not have the schematic for this fuel system on Yamaha it is simply a guess from my 31 yrs in automotive.