2004 SR Johnson 2 Stroke 9.9, 15, 25, 30 HP Outboards Service Manual, Page 194Get this manual
POWERHEAD CLEANING
CLEANING
IMPORTANT: Before inspecting or assembling
powerhead, all internal components must be perfectly clean and free of contaminantsRemove any carbon accumulation from exhaust port areasRemove any carbon accumulation from cylinder head combustion chambersIf 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
Use Gel Seal and Gasket Remover to remove all traces of gaskets, adhesives, and Gel-Seal II from the cylinder block and crankcase
CAUTION
To avoid piston or cylinder block damage, restore the chamfer to all port edges using ball hone or other suitable tool
Carefully remove any carbon accumulation from the tops and ring grooves of the pistonA ring groove cleaning tool can be made by breaking an old ring and grinding an angle on its endDo not damage ring grooves while cleaningThoroughly wash entire cylinder block and crankcase with warm, soapy water to remove all traces of contaminants