2003 Johnson ST 6/8 HP 4 Stroke Outboards Service Manual, PN 5005471, Page 208Get this manual
GEARCASE WATER PUMP Apply Nut Lock to the threads of the gearcase retaining screwsInstall and tighten the screws to torque of 96 to 120 inIbs(11 to 14 Nm)the impeller drive pin, gaskets (6 HP), and impeller plate1Drive pin Impeller plate
IMPORTANT: When installing gearcase on models with gearcase extension, do not tighten the retaining screws until the gearcase and the extension are properly aligned with the exhaust housing
Remove and discard the water tube grommet, 0ringand seal in the impeller housing (8 HP)
Inspection
Check impeller for overheating, hub separation and visible signs of wear or damageCheck impeller cup and plate for scoring, distortion, and impeller material transferInspect housing for cracks or melting