Honda Outboards BF40A/BF50A Service Manual, Page 201Get this manual
HONDABF35A45A
INSPECTION
STARTER MAGNETIC SWITCH ASSEMBLY
NOTE Be sure the battery is in good condition before performing this test
Connect the blackwhite wire of the starter switch to the positive (+) terminal of the battery and black wire to the negative (-) terminal and check for continuityThere should be continuity between the terminalsAnd then there should be no continuity when disconnecting the battery
FUSEFUSE CASE