Honda VFR800 Owner's Manual page 47

Petrol Containing Alcohol
If you decide to use a petrol containing
alcohol (gasohol), be sure it's octane rating
is at least as high as that recommended by
Honda. There are two types of ''gasohol'':
one containing ethanol, and the other
containing methanol. Do not use petrol that
contains more than 10 % ethanol. Do not use
petrol containing methanol (methyl or wood
alcohol) that does not also contain
cosolvents and corrosion inhibitors for
methanol. Never use petrol containing more
than 5 % methanol, even if it has cosolvents
and corrosion inhibitors.
40
Classic Cycles Technical Resources
The use of petrol containing more than 10 %
ethanol (or more than 5 % methanol) may:
Damage the painting of the fuel tank.
Damage the rubber tubes of the fuel line.
Cause corrosion of the fuel tank.
Cause poor drivability.
Before buying fuel from an unfamiliar
station, try to find out if the fuel contains
alcohol. If it does, confirm the type and
percentage of alcohol used. If you notice
any undesirable operating symptoms while
using a petrol that contains alcohol, or one
that you think contains alcohol, switch to a
petrol that you know does not contain
alcohol.