2001 Mercury Mariner 50-60HP Factory Service Manual, Page 84Get this manual
IGNITION
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 PressureEngine Over Heating:timing retards and fluctuates, rpm will remain below 2000 rpm (ECM) Low Oil PressureEngine Over Heating:timing retards and fluctuates, rpm will remain below 2000 rpm Ignition CoilHigh Tension Lead(s) Spark Plug Cap(s) Spark Plug(s) (ECM) Unit Ground Connection:(ECM)ignition coilstator Engine Hard To Start Cold Debris In Carburetor Enrichener Circuit Weak Spark Condition Throttle Plate in Open Position Weak Spark Condition Vapor Lock Low Oil PressureEngine Over Heating:timing retards and fluctuates, rpm will remain below 2000 rpm Stator Ignition CoilHigh Tension Lead(s) (ECM) Spark Plug(s) Charge Coil Ignition CoilHigh Tension Lead(s) Spark Plug Cap(s) Spark Plug(s) Ground Connection at:ignition coil(ECM)stator High Resistance To Ground at:stoplanyard sw(watercorrosion) (ECM) Boat Under Propped Propeller Hub Spun Perform Test No4 3