I agree with Ian. Especially the WM bikes. One of their design criteria was they should run well on crap gas. I have an eclectic collection of motorcycles and here in the US, all gas has at least 10% ethanol. I always add a small amount of Seafoam to each tank-full and don't seem to have any issues at all. Ethanol gas does seem to swell and weaken seals and 0-rings though.
