1998 Johnson Evinrude "EC" 90, 100C, 105C, 115, 150, 150C, 175 60 deg. LV Service Manual, P/N 520210, Page 46Get this manual
Idle Timing
1Disconnect the timing sensor plugAttach the O'VIC Ignition Analyzer from O'VIC Ignition Test Kit, PIN 434017, to the timing sensor2Move the analyzer selector switch to position:
3Connect the analyzer to 12-volt source
rn 4loosen the timer base detent screwrn 5Move both the inside and outside detent tabs completely forward on the detent plate[[] 6Be sure the timer base lever is against stop on the flywheel