Re: How often to change impeller?
I still wonder why Yanmar has made it so difficult to change something that should be an annual maintenance item. On my 4jh I have to remove the water pump and alternator.
I watched some whiz at a boatyard change it by hand one time, without removing anything, but he was able to twist his hands into godawful positions...plus he was a Yanmar mechanic and did it all the time and could do it blind. I tried that a time or two and always dropped screws or the plate and realized it was easier just to remove the alternator and then the water pump.
Still cuss Yanmar for putting it where it is...on the backside of the water pump. Last one I saw at the boat show was the same way.
Twenty years from now you will be more disappointed by the things y%^&*.....oh never mind. 90% of the people on sailing forums already use that as their signature! I'm not a conformist.