I NEED THE CORRECT P/N ....FOR MY 1996 MARINER 200 EFI (MAGEFI) S/N 0G425861... WATERPUMP ASSY I HAVE 3 P/N'S NOT SURE WHICH ONE IS RIGHT 18-3316,18-3317,OR 18-3319........ ALSO DOES THIS MOTOR HAVE A THERMOSTAT...... THE OLD PUMP LOOKS FINE AND I HAVEN'T CHANGED A THING ON IT EXSEPT FOR REGULAR MANT. ... BUT NOW THE ENG WANTS TO OVER HEAT WHEN RUNNING FAST DWN THE LAKE BUT NOT AT IDLE.. 
