Mercury Mariner 25HP 4-Stroke Outboard Service Manual 1997, Page 59Get this manual
'Recommended Test (1) OVA TEST (Direct Voltage Adapter) (2) OHM TEST (Resistance Testing) (3) Aeplace Component and Aetest (4) Mechanical TesVRepair PROBLEMCONDITION No Spark Condition (Both Cylinders) Probable Cause
Crank Position Sensor Stator (ECM) Stop Circuit Short to Ground:stop circuit lead lanyard stop switchtiller handle stop button (if supplied)
d- remote control harness
Perform Test No
2 1-2 1-2 1-3 3
Ignition Coil Primary Circuit Shorted to Ground Spark Plugs Open Ground Condition:ignition coil stator ground(ECM)
No Spark Condition (One Cylinder)
Weak Spark Condition