1998 Johnson Evinrude "EC" 9.9 thru 30 HP 2-Cylinder Outboards Service Manual, Page 225Get this manual
7Lightly oil pinion splines of the driveshaftSlide the driveshaft through the impeller housing and impeller until drive pin flat of the driveshaft is below the impeller8Align drive cam flat with groove of the impellerInstall the impeller drive cam Sharp edge CD of the cam is leading edge during driveshaft rotation Q)Slide the impeller housing down the driveshaftEngage the impeller with the cam
INote Verify that the impeller engages the impeller cam properlySerious powerhead damage will result if impeller cam is displaced 9Lightly coat both sides of new impeller plate gasket with OMC Gasket Sealing CompoundPlace gasket on the gearcase10Place the impeller plate over the gasket11Slide the driveshaft down into the gearcase and engage the pinion