1996 Ski-Doo Shop Manual, Volume 3, Page 231Get this manual
Section 06 ELECTRICAL ub-S ectio 03 (SPA PL S)
First unscre the spark plug turnCle an th spark plug and cylind er ead ith pressuriz air th en co mplet ely unscre wW INsin co pre sse air, lw ys ar rot ectiv r
A toocoldplug ill re sult in fouling (shorting th spark plug) or ay cre at carb on build up hich can eat up red-hot and cause pre-ignition or etonation;
Fouling of th spark plug is indicate by irre gular running of th ngin e, ecre ased engine spe ed du to misfiring, re duce erform anc e, and increase fu el consum ptionThis is due to loss of co pre ssionO th er ossible caus areprolonge idling, or running on too rich mixture due to faulty carburetor adjustm nt or incorrect fuel andor fu el mixingTh plug fac of fouled spark plug has either dry coating of soot or an oily, glossy coating given by an xce ss either of oil or of oil ith sootSuch coatings form conductive connection be en the center electrode and ground
Th proper operating perature or he at range of th spark plugs is etermine by th spark plug ability to dissipate the he at ge nerate by co mbustionTh longer th heat path et the electrode tip to the plug shell, the hotter the spark plug operating te perature ill and inversely, the short er th at path, th colder th op erating te erature ill becoldtype plug has relatively short insulator nose and transf ers he at very rapidly into th cylinder headSuch plug is used in eavy duty or continuous high spe ed operation to avoid overhe atingThhottype plug has longer insulator nose and transfers he at ore slo ly ay fro its firing endIt runs hotter and burns off co bustion de posits hich might te nd to foul th plug during prolonge idle or low spe ed operation