2004 Bombardier Quest/Traxter Series Shop Manual, Page 346Get this manual
Section 06 ELECTRICAL Subsection 05 (IGNITION SYSTEM)
Traxter Series When every other components above have been tested and are good, the MPEM can be suspectedEnsure wiring and connectors are in good condition prior to replacing the MPEM
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
IGNITION TIMING