Mercury Mariner 25HP 4-Stroke Outboard Service Manual 1997, Page 49Get this manual
Specifications Type Spark Plug Type (NGK) Spark Plug Gap Firing Order Ignition Timing: Fully Relarded (Below 800 RPM) Fully Advanced (6000 RPM) Charge Coil Resistance Crank Position Sensor Resistance Ignition Coil Resistance: Primary Secondary (Wo Bools) ECM Engine Speed Limiter Soft Reduction (Relards Timing) Spark Cut-Out Reduction (Percentages of ignition spark are Cut-Out) ECM OverheatLow Oil Pressure Speed Control