Spark Plugs - Polaris SLT780 1996 Owner's Safety And Maintenance Manual

MAINTENANCE
Spark Plugs
The recommended spark plugs to
be used in this watercraft are
BPR8ES. The correct gap is .028
in.1.7 mm and should be measured
with a wire thickness gauge. Alter-
nate spark plugs include: Cham-
pion RN3C and ND W24ESR-U.
The color of a used spark plug is indicative of the way the engine is running.
A slightly brownish tip is considered good. The engine is running properly and the
carburetor is adjusted correctly.
A black tip indicates several potential problems: the wrong spark plug (wrong heat
range) is being used; excessive idling; carburetor idle speed mixture or high speed
mixture is too rich; or there is a malfunction with the
RPM
limiter.
A light grey or white tip indicates: the wrong spark plug (wrong heat range) is being
used; carburetor idle speed mixture is too lean; there is a plugged fuel filter; or there
is a leaking engine seal or gasket.
A yellow tip is caused by salt water mist ingestion. This is a conductive coating
which will eventually cause fouling. This is a normal situation.
If the spark plug tip is black or grey have the watercraft serviced by an authorized
Polaris dealer as soon as possible.
A spark plug with cracked porcelain or damaged threads should be changed im-
mediately. If the electrodes are badly worn or burned the plug should also be re-
placed.
If the spark plug is in good condition, clean it with a clean shop cloth and/or wire
brush. Adjust the gap to .028 inl.7 mm using a wire thickness gauge.