Mercury Mariner 200, 225 Optimax Outboards Service Manual, 90-855348, Page 227Get this manual
10If suitable powerhead holding fixture is available, powerhead may be removed fully dressedDisconnect thermostat hoses, fuel rail air outlet hose, fuel cooler water hose and tell-tale hose NOTE: If powerhead cannot be removed due to gasket adhesion, reinstall fore and aft powerhead nutsInstall jacking block under the aft powerhead nutPlace pry bar under the forward powerhead nutUnscrew the aft nut against the jacking block while prying up on the forward nut to break the gasket adhesion