1978 Ski-Doo Shop Manual, Page 325Get this manual
SECTION 05 SUB-SECTION 04, (ELECTRIC STARTER)
SYMPTOM Starter does not turn
CAUSE Poor contact of starter switch contact pointsBurnt or poor contact of solenoid switch contact discOpen circuit of solenoid switch pull-in windingOpen circuit of solenoid switch hold-in windingPoor contact of brushBurnt out commutatorCommutator mica too highShorted field coilShorted armatureWeak brush spring tensionWorn bushingsWeak batteryShorted battery celltslPoor contact of battery terminalts)Open circuit between starter switch and solenoid switchPoor battery ground cable connection
REMEDY Repair or replace switch
Starter turns; but does not crank the engine
Replace solenoid switchReplace solenoid switchReplace solenoid switchStraighten commutator and brushTurn commutator irr latheUndercut micaRepair or replace yokeRepair or replace armatureReplace springReplace bushingsRecharge batteryReplace batteryClean and tighten terminal ts)RepairClean and tighten(