Polaris MSX 110 Owner's Manual For Maintenance And Safety page 89

MAINTENANCE AND LUBRICATION
Spark Plugs
Always use the recommended spark plugs for your
Polaris watercraft, and make sure the spark plug gap is
within specification. Refer to the specifications
section beginning on page 102 for the recommended
spark plug type for your watercraft.
CAUTION
Using non-recommended spark plugs can result
in serious engine damage. Always use the spark
plugs recommended for your Polaris watercraft.
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Spark plug condition is indicative of engine operation.
The spark plug firing end condition should be read
after the engine has been warmed up and the vehicle
has been driven at higher speeds. Immediately check
the spark plug for correct color.
S A slightly brownish tip is considered normal. The
engine is running properly.
S A yellow tip is caused by salt water mist ingestion.
This conductive coating will eventually cause foul-
ing. This is a normal situation.
NOTE: If the spark plug tip is black or grey, have the
watercraft serviced by an authorized Polaris
dealer as soon as possible.
S A black tip indicates several potential problems: the
wrong spark plug (wrong heat range) is being used;
excessive idling occurs; the oil has been overfilled
or the RPM limiter is malfunctioning.
S A light grey or white tip indicates that the wrong
spark plug (wrong heat range) is being used; a fuel
filter is plugged or an engine seal or gasket is leak-
ing.