Thanks for that explanation Luddite, you've just surfaced a whole bunch of memories from when I used to work in service stations around the time ethanol blends were introduced by Mobil (Esso in NZ, basically). It didn't cross my mind, and yeah, it's E5, and I suspect the lock-up at my old flat wasn't particularly dry!
I'll get a jerry can to drain it off tomorrow and replace with some decent fuel. Need to dispose of the old fuel somewhere - I'm sure I've got some weeds or moss that needs killing
