You may recall I experimented with these on the ONAN and they didn't last any longer than the stock impellers. I even changed the 2-piece ONAN pump housing for one piece Sherwood pump - no difference.
I've bought a 220VAC March centrifugal pump which I'm going to plumb in for the ONAN and end impeller issues forever.
I've not had impeller issues on the Yanmar...and I never had on my previous boat either
