1988-1995 Mercury Force 5HP Outboards Service Manual, 90-823263 793, Page 189Get this manual
7Install impeller Install impeller drive pin (A) through hole in driveshaftPut light coat of grease (FT-2961) on impeller vanesSlide impeller (8) on driveshaft (drive pin notches down) down over impeller drive pin NO TE: Be sure to hold impeller in place on driveshaft