Mercury Mariner Service Manual 6, 8, 9.9 210CC Sailpower, Page 8Get this manual
Flushing Engine
SUBMERGED WHILE RUNNING (SPECIAL INSTRUCTIONS)
When an engine is submerged while runningthe possibility of internal engine damage is greatly increasedIf, after engine is recovered and with spark plugs removedengine fails to turn over freely when turning flywheel, the possibility of internal damage (bent connecting rod andor bent crankshaft) existsIf this is the case, the powerhead must be disassembledSUBMERGED ENGINE (FRESH WATER) (PLUS SPECIAL INSTRUCTIONS)