1997 Johnson Evinrude "EU" 9.9 thru 30 2-Cylinder Service Manual, P/N 507263, Page 171Get this manual
Cleaning
INote Before
inspecting or assembling powerhead, all internal components must be perfectly clean and free of contaminants1Remove any carbon accumulation from exhaust port areas
2Remove any carbon accumulation from cylinder head combustion chambers3If cylinder walls are glazed from extended use, use medium grit hone to resurface wallsUse slow RPM to achieve strong "crosshatch" pattern for best oil retention and ring sealing
INote To
avoid piston or cylinder block damage, restore the chamfer to all port edges using ball hone or other suitable tool
avoid personal injury, wear eye protection and rubber gloves when using OMC Gel Seal and Gasket Remover