1992 Johnson Evinrude "EN" 60 thru 70 Service Manual, P/N 508144, Page 142Get this manual
Cleaning
Before inspecting or assembling powerhead, all internal components must be perfectly clean and free of contaminants1Remove any carbon accumulation from exhaust port areas2Remove any carbon accumulation from cylinder head combustion chambers3If cylinder walls are glazed from extended use, use medium grit cylinder hone to resurface wallsUse slow RPM to achieve strong "crosshatch" pattern for best oil retention and ring sealing
avoid piston or cylinder block damage, restore the chamfer to all port edges using ball hone or other suitable
'" To avoid personal injury, wear eye protection and rubber gloves when using OMC Gel Seal and Gasket Remover
r:;l4Use OMC Gel Seal and Gasket Remover to remove all traces of gaskets, adhesives, and OMC Gel Seal II from the cylinder block and crankcase