I've got the old '66 110 running finally. However, I had a service guy tell me I needed to change the water impeller badly. He claims it needs to be done every 3 years (& I'm guessing the orginal '65 impeller is on there).<br />The engine runs fine, doesn't overheat & I get a solid stream out the pee-hole & it spits even more out of the secondary exhaust port under the motor.<br />The guy who told me knows what he's talking about, but I don't wanna mess up something if it's working fine. Is this really necessary? Thanks...