Bombardier SeaDoo 1997 factory shop manual, Page 170Get this manual
Section 07 ELECTRICAL SYSTEM Sub-Section 02 (IGNITION SYSTEM)
All Models Except SP, GTS and HX As an alternate method, use KOWA ignition coil tester (or equivalent), available from after-market toolequipment suppliers
Heat Range
The proper heat range of the spark plugs is determined by the spark plugs ability to dissipate the heat generated by combustionThe longer the heat path between the electrode tip to the plug shell, the hotter the spark plug operating temperature will be and inversely, the shorter the heat path, the colder the operating temperature will beA "cold" type plug has relatively short insulator nose and transfers heat very rapidly into the cylinder headSuch plug is used in heavy duty or continuous high speed operation to avoid overheatingThe "hot" type plug has longer insulator nose and transfers heat more slowly away from its firing endIt runs hotter and burns off combustion deposits which might tend to foul the plug during prolonged idle or low speed operation-
CAUTION
Do NOT use coil tester on metal work benchFollow manufacturer instructions1With ignition coil removed from craft, disconnect spark plug caps from high tension cables2Hook high tension leads from tester to ignition coil high tension cables3Connect smaller tester leads to primary of ignition coilON OFF 12 V