You're welcome - i hope it is something as simple as that!
Maybe i should start adding some sort of petrol treatment to my lawnmower as well. I don't really know anything about Allen scythes but something in my memory cell says they're pretty old these days, chances are the rubber is a slightly different formulation so may be immune to ethanol.
Maybe now we're exiting the EU we can tell them what to do with their ethanol in petrol!