1999 "EE" Evinrude 70HP 4-Stroke Service Manual, P/N 787023, Page 52Get this manual
CKP (Crankshaft Position) Sensor
There are two Crankshaft Position sensors installed under the flywheelA reluctor bar is located on the flywheel side-wallThe sensors and bar interact to signal the ECUTwo sensors provide better starting ability than one sensorThe ECU detects the crankshaft angle for #1 and #4 cylinders according to the signal from one sensorThe other sensor sends signal for #2 and #3 cylinders Crankshaft angle is considered as piston positionNotethe engine will run well on only one sensor, however the tachometer will in dicate 112 the normal RPM The CKP sensors are magnetic type sensorsThey convert changes in an electromagnetic field into voltage signal, then send it to the ECUThey're similar in design and function to CMP sensor
CMP (Camshaft Position) Sensor
The Camshaft Position sensor is mounted on top of the cylinder head reluctor bar is fitted on the top edge of the camshaft pulleyThe CMP sensor sends pulse signal to the ECU that is generated from the reluctor bar once per camshaft rotation The ECU uses signals from the CMP sensor and the CKP sensors to determine cylinder number and control sequen tial injectionThe ECU receives four digitized crankshaft position signals while receiving one camshaft position signalThis is magnetic type sensor that converts changes in an electromagnetic field into voltage signal, then sends it to the ECUIt's similar in design and function to CKP sensorThe signals from the CMP and CKP sensors relate to the following: Fuel Injection TimingDuration Fuel Pump Operation Ignition Timing Tachometer Operation lAC Valve Operation