Honda HRC216 Owner's Manual page 24

5. PRE-OPERATIOM CHECK
Fuel Recommendation
Pump octane rating: 86 or higher.
We recommend unleaded fuel because it produces fewer engine and spark plug
deposits and extends exhaust system life
Never use stale or contaminated gasoline or an oil/gasoline mixture Avoid getting
dirt or water in the fuel tank.
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 lawn mower dealer.
IMPORTANT NOTICE
Running the engine with persistent spark knock or
pinging can cause engine damage.
NOTE: Running the engine with persistent spark knock or pinging is considered
misuse,
and the Distributor's Limited Warranty does not cover parts damaged
by misuse
GASOLINES CONTAINING ALCOHOL
If you decide to use a gasoline containing alcohol (gasohol), be sure its pump
octane rating is 86 or higher. There are two types of "gasohol": one containing
ethanol, and the other containing methanol.
I MPORTANT NOTICE I Using gasohol that contains more than 10% ethanol,
or gasoline containing methanol (methyl or wood alcohol) that does not also
contain cosolvents and corrosion inhibitors for methanol, can cause serious fuel
system damage and poor engine performance.
Never use gasoline containing more than 5% methanol, even if it has cosolvents
and corrosion inhibitors.
Honda does not endorse the use of fuels containing methanol, since evidence
of their suitability is as yet incomplete
NOTE: Fuel system damage, or engine performance problems resulting from the
use of fuels that contain alcohol, is not covered under the warranty.
Before buying fuel from an unfamiliar station, first determine if the fuel contains
alcohol; if it does, find out the type and percentage of alcohol used.
NOTE: If you notice any undesirable operating symptoms while using a gasoline
that contains alcohol, or one that you think contains alcohol, switch to a gasoline
that you knoti does not contain alcohol.
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