1998 Johnson Evinrude "EC" 90, 100C, 105C, 115, 150, 150C, 175 60 deg. LV Service Manual, P/N 520210, Page 42Get this manual
10Mark the location of the !nside detent tab on the detent plate11Leave the timer base detent screw loose for next adjustment INotel
This procedure should provide the best idle characteristics while allowing engine idle speeds in gear ranging from 600 to 700 RPM, depending on propeller selection If idle speed is too high, check induction system for air leaks If idle speed is too low when engine condition is correct, decrease idle timing to achieve desired RPMExample: from ATDC to ATDC If idle speed is inconsistent or the engine runs rough or spits lean, refer to Carburetor Mixture Adjustment, Section 2
Maximum Spark Advance
1Verify that the spark lever screw is still loose
2Manually advance the spark cam to wide-open-throttle position using the spark lever