1999 "EE" Evinrude 70HP 4-Stroke Service Manual, P/N 787023, Page 50Get this manual
During IdlingTrolling: In this mode, ignition timing is controlled within 6_14 BTDCWhen the CTP (Closed Throttle Position) switch is "ON", the ECU changes ignition timing very often It keeps engine speed stable at 700 RPM based on RPM signals from the CKP (Crankshaft Position) sensorsNote that ignition timing will remain fixed at BTDC if engine speed exceeds 1000 RPM in NEUTRAL
During Normal Operation:
Ignition timing is controlled within 10-36 BTDC, depending on engine operating conditions
During Acceleration:
Ignition timing is controlled by the ECU using thenormal ignition timing map" in accordance with signals from the MAP, CKP, and Cylinder Temperature sensors
During Deceleration:
Ifthe throttle valve is suddenly closed, and the CTP switch is "ON", ignition timing is delayed for programmed duration to prevent stalling or unstable runningDuring normal deceleration, ignition timing is controlled by the ECU to retard timing from the "normal ignition timing map"
IgnitionElectrical Components