1997 "EU" Johnson Evinrude 5 thru 15 Four Stroke Service Manual, P/N 507262, Page 94Get this manual
Ignition Module
The ignition modulepower pack has several basic functionsIt stores and distributes the voltage received from the charge coilThe ignition module uses an electronic switch, activated by the timing sensor, to energize ignition coil primary windingThe power pack uses electronic switches (SCRs), activated by sensor coil output, to select the correct ignition coil primary winding for firingThe ignition modulepower pack has an RPM limiting circuit which helps protect against powerhead damage due to overrevvingOverrevving can result from: Installing the motor too high Carrying less weight than the motor is propped for Using propeller that is too small, has very worn blades, or ventilates excessively The ignition modulepower pack incorporates the S.L.OWwarning systemThis system gradually limits engine speed to approximately 2000 RPM when either the: Engine temperature switch closes (Remote Control Models) Crankcase oil pressure drops to dangerously low level Once the S.L.OW warning system has activated, the engine must cool to allow the temperature switch to open or crankcase oil pressure must be restoredThe engine must be operated below 1500 RPM before normal operation can be resumedStop Circuit