Mercury Mariner 8/9.9HP 4-Stroke Factory Service Manual, Page 45Get this manual
Recommended Test (cont (1) DVA TEST (Direct Voltage Adapter) (2) OHM TEST (Resistance Testing) (3) Replace Component and Retest (4) Mechanical TestRepair PROBLEMCONDITION Timing Will Not Advance Probable Cause Low Oil Pressure:timing retards and fluctuates, rpm will remain below 2000 rpm (CDI) Unit 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) (CDI) Unit Ground Connection:(CDI) unitignition coilstator Debris In Carburetor Enrichener Circuit Weak Spark Condition Throttle Plate in Open Position Weak Spark Condition Vapor Lock Low Oil Pressuretiming retards and fluctuates, rpm will remain below 2000 rpm Stator Ignition CoilHigh Tension Lead(s) (CDI) Unit Spark Plug(s) Charge Coil (CDI) Unit Ignition CoilHigh Tension Lead(s) Spark Plug Cap(s) 5k Resistor Spark Plug(s) Ground Connection at:ignition coil(CDI) unitstator High Resistance To Ground at:stop lanyard switch(watercorrosion) Perform Test No4 1-3