Mercury Mariner 4 and 5HP 4-Stroke Outboards Service Shop Manual 1999, Page 48Get this manual
IGNITION SYSTEM
Description
A single cylinder capacitor discharge ignition (C Olsystem is utilized on this modelMajor components of this system are the flywheelmagneto, capacitor charging coilCOl unit, ignition coil and spark plugA stop switch is provided which shorts the trigger coil to ground preve nting ignition from taking place
Test Procedures
IMPORTANT: When using an ohmmeter for any resistance test, always zero meter movement whenever scales are changed IMPORTANT: If engine misfires, runs rough or does not start, the ignition system should be checked with volt meter capable of measuring 400 VDe or higher and direct voltage adaptor (91-89045) or multi-meterOVA tester (91-99750)Follow instructions In test manual included with OVA or multi-meter OVA tester
Direct Voltage Adaptor Specifications