1998 Mercury 9.9/15HP 4-stroke outboards factory service manual, Page 62Get this manual
IGNITION
PROBLEMCONDITION Timing Will Not Advance
Probable Cause Low Oil Pressure:timing retards and fluctuates, rpm will remain below 2000 rpm (ECM) Low Oil Pressure:timing retards and fluctuates, rpm will remain below 2000 rpm Ignition CoilHigh Tension Lead(s) Spark Plug Cap(s) 5k Resistor Spark Plug(s) (ECM) Unit Ground Connection:(ECM)Ignition coilIgnition charge coil Low Oil Pressure:timing retards and fluctuates, rpm will remain below 2000 rpm Ignition Charge Coil Ignition CoilHigh Tension Lead(s) (ECM) Spark Plug(s) Ignition Charge Coil Ignition CoilHigh Tension Lead(s) Spark Plug Cap(s) 5k Resistor Spark Plug(s) Ground Connection at:Ignition coil(ECM)Ignition Charge Coil High Resistance To Ground at:stoplanyard switch (watercorrosion) (ECM) Ground Connection at:Ignition Coil Primary LeadsIgnition Charge Coil(ECM) Primary Coil Supply Leads High Resistance To Ground at:stoplanyard switch (watercorrosion) Weak Ignition Charge Coil Ignition CoilHigh Tension Lead(s) Spark Plug(s) Spark Plug Cap (Resistor) Spark Plug Cap Leak (ECM) Failure