Stupid cavitation question

[ImpulsiveJames]

Ok, so I got a ski last year and been working through issues regularly. I finally got the engine in tip-top condition, but now I'm hitting the Rev limiter at about half throttle.

I just finished sealing stuff up and had a question before I go out on the river again.

If you fix the cause of cavitation (wear ring in this case), what happens if you run the old pitted impeller? Will the cavitation continue?

(Yes, I know the impeller is shot, but I'm curious if you can tell if there problem is fixed before running out and buying a new impeller)

 

[Mraw]

That impellar will cause cavitation, make sure when you replace the wear ring to get a new neoprene seal as well.

 

[Legacy37]

curious as to the answer... myself

 

[mikidymac]

That isn't a seadoo impeller?

But to answer your question, no the pitting will not cause cavitation, they are the result of the cavitation. When you have bad or disrupted flow in the jet pump it causes a low pressure area and this low pressure actually allows the water to boil at room temperature which creates steam bubbles and then these bubble implode at supersonic speeds. This supersonic implosion actually has enough force to hammer and burn away the metal leaving the holes burnt into the metal that you see in your picture.

Now an aluminum impeller like that has much more surface area and the blades can't be made thin because the lack of strength of aluminum which is why all good impellers are stainless steel. So basically aluminum impellers are low performance and low price typically found on Base Model skis to lower the price.