Hi,<br /><br />I am unsure of the factors that determine when a water impeller needs replacing. Besides having a steady stream of water coming from the motor as an obvious sign, does the water impeller still need replacing after a number of years or after an amount of usage?<br /><br />The motor I have is a Merc 115 1979 Blueband (v6).<br /><br />Any help is appreciated.<br /><br />------------------