Honda BF50 (5HP), BF5A Outboard Motors Shop Manual 2014, Page 100Get this manual
3WATER PUMP
DISASSEMBLYASSEMBLY
IMPELLER HOUSING WATER TUBE SEAL RING 28 mm HEXBOLT (4) ASSEMBLYApply SEA LOCK #10 (locking agent) to the thread before installingASSEMBLY: Align the flat surface in the center of the impeller with the flat side of the pinion haft
PUMP IMPELLER ASSEMBLYCheck for wear or cracksInstall the impeller in the impeller housing while turning it counterclockwiseIMPELLER HOUSING