Me again, thanks for the replies. There,s no rust in the tank but you can see where the petrol has evaporated and has left like a coating behind. My fuel tap was also faulty but I've replaced it. Having said that I've never turned the fuel off on any 2 strokes I've owned before. so how do i check the float levels? What should they be at and how do i adjust them?

Cheers y'all.