1974 Ski-Doo Shop Manual, Page 209Get this manual
SYMPTOM: Firing on one cylinder only Before checking circuit, make sure high tension wires and spark plugs are in working orderG)Check cut -out button operation by disconnecting junction block(!)and by starting engineIf both cylinders are firing, replace defective cut-out button If not, proceed with following test0Disconnect electronic box junction block and check each pick-up coil by connecting an ohmmeter between ground and points0(points0are in the junction block, not in the elect ronic box}Reading must be between 55 to 60 ohmsIf not, armature plat assembly should be re placedIf reading is ithin limits, the electronic box is defective and must be replaced