Re: Yanmar waterpump impeller
I just bought the bits for mine too, they sure are small compared to the normal ones I take apart on powerboats.
I got a nice discount, buying 2 sets of everything(air-filter, oil-filter, fuel filter, impeller and gasket). Worth replacing them all if it's been a while, then start the clock from there. My air filter looked ok at first, but the foam was so degraded it was getting sucked into the intake in small pieces.
The 2nd set I already sold to someone else, when they saw me starting they decided to do the same, otherwise it would have been spares.
While you're at it, I'd replace the o-rings in the sea-strainer at least, or possibly replace the whole thing, if it's like my ancient Vetus one(hard to get parts, all plastic).