Honda Outboards BF40A/BF50A Service Manual, Page 130Get this manual
HONDA BF3I5A45A
cPRIMARY DRIVE GEAR
1) Record the right end number of the primary drive gear J.D number
[1] PRIMARY DRIVE GEAR 1.0NO
2) Determine the primary drive gear I.Dcolor and select the proper primary drive gear by referring to the primary drive gear I.DnumberPrimary drive gear I.DNoPrimary drive gear I.D color