High engine rpm, low speed

[Danno115]

I have a new to me 2010 challenger 215 with 85 hours and noticed when I used it last that the engine revs very high 8500-9000 rpm with little speed 25-28 mph. I replaced the wear ring which had some grooves cut into it around the impeller but not overly damaged I don't think. Is there anything else to check on while the pump is out? I've read that the carbon seal may be damaged but with 85 hours it doesn't seem likely and i'm not entirely sure how to check the carbon seal for damage. Is there anything obvious to look for? I don't want to just throw parts at it unless there's no other option. Thanks!!

 

[go_panthers]

It doesn’t have to be a large piece to cause major cavitation. These hits of wood brought me to a crawl a few years ago.

This is looking into the intake from under the boat. I used a long pry bar to knock them out.

 

[beergut]

like mentioned above- even the smallest groove or nick in the impeller or ring will cause cavitation and loss of speed- how do the pumps vanes look? I'm in the process of replacing my pump- it's a long story

 

[Danno115]

yes the vanes on my pump had some oxidization but all in all not too bad. Cleaned them with a wire brush and put a light coat of triple guard grease on the surface. Still haven't tested out the new wear ring yet, weather and no fuel at the marina last week. Hopefully tomorrow is the day. Thanks for the help and suggestions.