So I just put my new engine in and took the boat out for the first time the other day, and when I brought it back I was checking out the jet and discovered the pictured damage. The engine is making 528hp (dyno) and the impeller was a new aluminum Berk B, spinning 5600rpm in an E pump. I don't have a loader yet, so I did get some cavitation when I'd punch it, but I never held it down when it would slip. I only had the boat in the water for about 30 minutes. I had no symptoms and no vibration.
Is it just too much HP for an aluminum impeller or is this entirely from cavitation?
Looks like you got some trash between the impeller and wear ring and it snowballed, suprised to see that with a plastic wear ring. You need a new impeller for sure. That is not from horsepower or cavitation.