1972 Ski-Doo Shop Manual, Page 212Get this manual
3-04-06 MERCO-O-TRONIC LIGHTING COIL 1Turn selector switch to position no2 (DISTRIBUTOR RESISTANCEfor checking low ohm values)2Turn meter adjusting knob for scale no2 until meter pointer aligns with set position on right side of scale3On engines equipped with 40 watt lighting coil, proceed as follows:
5On double cylinder engine, carry out the following procedure: a) Connect the black test lead to one breaker points terminalb) Connect the red test lead to the other breaker points terminal (fig3-4-11)Red
Connect the black test lead to armature plate (ground)b) Connect the red test lead to the yellow green wire
4On all other engines, carry out the following procedure: a) Connect the black test lead to one of the yellowgreen wiresb) Connect the red test lead to the other yellowgreen wire