Normally i would say to drain the fuel out Peters but i meant only a tiny ammount, like about 1-2miles worth of riding. Ideally yes drain it before refilling it. Just saying tho the 2 scoots i saved in the past had both sat years with a tiny ammount of fuel in them, one had a plastic tank but the other had steel. Both still run great now and have never missed a beat, i know because i sold one to my neighbour and still own the other, not my A50. I checked the steel tank recently cos im rebuilding that scoot and it is nice and clean inside with zero rust. Maybe i got lucky, just sayin tho, it worked for me. Ideally tho youre right, if you can then drain out the old fuel and replace it.