1997 Johnson Evinrude "EU" 90, 105RW, 115, 150, 150W, 175 60 LV Service Manual, P/N 507268, Page 105Get this manual
General Safety Warnings
Before working on any part of the ignition system, read the section called Safety at the end of this manualThe timing wheel cover is machinery guardUse caution when conducting tests on running enginesDo not wear jewelry or loose clothingBefore working on or removing any electrical parts, disconnect the battery cables at the battery to prevent electrical sparksTwist and remove all spark plug leads to avoid accidental starting while servicing enginePerform all high voltage tests on wooden or insulated bench top to prevent leakage or shock hazardsTo prevent possible fire and explosion under the engine cover, make sure ignition and electrical wires are routed and clamped in original position, away from rotating parts, which could cut or abrade wire insulationIf necessary to remove the spark plugs, be sure to keep the spark tester away from open spark plug holesReplace any locking fastener (locknut or patch screw) if its locking feature becomes weakDefinite resistance to tightening must be felt when reusing locking fastenerIf replacement is indicated, use only authorized replacement or equivalent