1968 Evinrude Big Twin, Big Twin Electric, Lark 40 HP Outboards Service Manual, Page 35Get this manual
DISASSEMBLV OF MAGNETO components removed from the armature plate removing the attaching screwsThe spark plug high tension leads puHed from the and lamination assemblies
Dirt, foreign particles, and are very detrimental to contact performanceThe oils and acids from person' hand, even though clean, affect contact resistance deposits the points wiH cause them to burn out after very short period operationIf points need cleaning, use alcohol or trichlorethyleneNEVER FILE POINTS - replace themremove any traces of dirt from contacts, insert strip bias tape and work it and down between the pointsRepeat entire cleaningprocedure for second set of points
CLEANING, INSPECTION, AND REPAIR
PLUGS Inspect plugs for cracked porcelain and worn electrodesClean the electrodes with point DO NOT sandblast spark plugsAdjust gap to the specified .030 inr-hIn re-gapping, adjust only the ground side electrfJde, as attempting to bend the center electrode will crack the insulatorSee Figure 4-7Poor ffiGtor performance and premature spark plug failure result from improper spark plug installation