Honda EW171 Owner's Manual page 27

Occasionally you may hear light "spark knock" or "pinging" (metallic rapping
noise) while operating under heavy loads. This is no cause for concern.
If spark knock or pinging occurs at a steady engine speed, under normal load,
change brands of gasoline. If spark knock or pinging persists, see an
authorized Honda generator dealer,
I
NOTICE
I
Running the engine with persistent spark knock or pinging can
cause engine damage.
Running the engine with persistent spark knock or pinging is misuse, and the
Distributor's Limited Warranty does no2 cover parts damaged by misuse.
Oxygenated Fuels
Some conventional gasolines are being blended with alcohol or an ether
compound. Thes'e gasolines are collectively referred to as oxygenated fuels.
To meet clean air standards, some areas
of
the United States and Canada use
oxygenated fuels to help reduce emissions.
If you use an oxygenated fuel, be sure it is unleaded and meets the minimum
octane rating requirement.
Before using an oxygenated fuel, try to confirm the fuel's contents.
Some states/provinces require this information to be posted on the pump.
The following are the EPA approved percentages of oxygenates:
ETHANOL- (ethyl or grain alcohol) 10% by volume
You may use gasoline containing up to
10%
ethanol by volume.
Gasoline containing ethanol may be marketed under the name
Gasohol.
MTBE- (methyl tertiary butyl ether) 15% by volume
METHANOL- (methyl or wood alcohol) 5% by volume
You may use gasoline containing up to 15% MTBE by volume.
You may use gasoline containing up to 5% methanol by
vcllurne as long as i't also contains cosolvents and corrosion
inhibitors to protect the fuel system. Gasoline containing more
than 5% methanol by
volume
may cause starting and/or
performance problems. It may
also
damage metal, rubber, and
plastic parts of your fuel system.
If you notice any lundesirable operating symptoms, try another service station
or switch to another brand of gasoline.
Fuel system damage or performance problems resulting from the use of an
oxygenated fuel containing more than the percentages of oxygenated men-
tioned above are not covered under warranty.
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