1978 Ski-Doo Shop Manual, Page 294Get this manual
SECTION 05 SUB-SECTION 03, (MERC-O-TRONIC TEST) (
TEST NO.4 IGNITION COIL RESISTANCE (PRIMARY)
1Turn selector switch to position no2(DISTRIBUTOR RESISTANCEfor checking low ohm values 2Connect the black test lead to no15 terminal of the ignition coil3Connect the red test lead to no1 terminal of the ignition coil4Read the RED figures on scale no2Meter reading must be between specification limitsIf not, replace the defective coilPRIMARY RESISTANCE: 1.9 Ohms