Mercury Mariner 200, 225 Optimax Outboards Service Manual, 90-855348, Page 81Get this manual
IMPORTANT: Depending on the polarity of the ohmmeter, reversed readings may be obtained I.E- CONTINUITY is observed when the NEGATIVE lead touches the POSITIVE stud and NO CONTINUITY is observed when the POSITIVE lead touches the POSITIVE studIMPORTANT: The regulator, rectifier and brush assembly are the only components individually replaceable on this alternatorIf the rotor or stator is defective, the entire rotor, stator and housing must be replaced as an assemblyIMPORTANT: Clean anti-corrosion paint from electrical connections prior to reassemblyCoat all electrical connections with LIQUID NEOPRENE (92-25711-1)ROTOR TEST 1Inspect slip ring surface for roughness, abnormal wear andor burningIf such conditions exist, rotor is not considered serviceable and alternator should be replaced 2Measure the outer diameter of the slip rings using vernier calipersSTANDARD DIAMETER: 0.567 in(14.4mm); MINIMUM DIAMETER: 0.551 in(14.0mm)If slip ring diameter is less than minimum, rotor is not considered serviceable and alternator should be replaced