Honda Outboards BF40A/BF50A Service Manual, Page 198Get this manual
HONDA BF3EiA45A
SHORT CIRCUIT TEST -CORE-TO-COMMUTATOR Check for continuity between the commutator and armature coil coreIf continuity existsreplace the armature
SHORT CIRCUIT TESTSHAFT-TO-COMMUTATOR Check for continuity between the commutator and amature shaft If there is continuity, replace the armature