I recently changed the wear plate on the raw water pump on the Yanmar. I have about 1675 hours on the engine and the plate showed significant scaring and wear. It was an easy change-out. After removing the impeller the plate simply sits behind it and is easily removed with a dental pick/ bearing pick/ or toothpick. I also added the Speedseal Life cover. Nice device.
The wear plate made a difference. Upon startup after an impeller change before changing the wear plate out, I would sometimes need to rev up the engine to get water to initially flow. Post change out, it was instant flow again as new.
B43, hull #9