cavitation??

[NORCAL68]

hi im a newb to Seadoo boats,so can someone explain what cavitation is and should l change my impeller if my boat struggles to get plaining even with 2 people at times.

 

[nswillin]

Cavitation is a loss of pressure with in a pump system. First sign of it is when you have the engine rpms up and the boat is not going as fast as it should. Kinda like a car with the clutch going out. It's reving up, but it's not going anywhere.
Most of the time a wear ring is at fault and is a pretty simple fix. If the wear is out of clearance, you are losing a lot of water pressure between it and the impeller causing it not not respond as well. Impellers do get worn out as well, Check all the blades for dings or bent blades, replace if real bad. If it is minor, a Prop shop should be able to fix it up for ya.

 

[MooF]

I had the misfortune of sucking up some small stones over the weekend. The impeller had a bad vibration to it and it felt like I did some serious damage. Visually the impeller looks 'ok' to the untrained eye, and I'm not sure how perfect its supposed to be after only 15hrs of use?
I don't have the ski here otherwise I would certainly post a pic. But what's interesting is that when we brought it home, the highway drive on the trailer must have jarred loose one last stone, because it was sitting on the inside of the intake grate, by itself. I'm wondering if the impeller was not even damaged but the one last stone was causing the cavitation issues.

Point here is that I've already brought the jet into the shop for inspection. I'm sure they'll tell me I need a new impeller, but hopefully a prop-fix would be sufficient...
Thoughts?

 

[shoe07]

I had the misfortune of sucking up some small stones over the weekend. The impeller had a bad vibration to it and it felt like I did some serious damage. Visually the impeller looks 'ok' to the untrained eye, and I'm not sure how perfect its supposed to be after only 15hrs of use?
I don't have the ski here otherwise I would certainly post a pic. But what's interesting is that when we brought it home, the highway drive on the trailer must have jarred loose one last stone, because it was sitting on the inside of the intake grate, by itself. I'm wondering if the impeller was not even damaged but the one last stone was causing the cavitation issues.

Point here is that I've already brought the jet into the shop for inspection. I'm sure they'll tell me I need a new impeller, but hopefully a prop-fix would be sufficient...
Thoughts?

next time you beach your ski, walk it out away from shore and rock it forward and back, side to side, so you can get the stuff out, 30 seconds of this saves time and money, sand rocks and sticks can all damage the impeller and wear ring

 

[MooF]

"Beaching" is ok if you have a decent shoreline with little debris. Ramping it where I did with the unit powered up was my error...I should have killed it long before reaching shore.

Turns out the impeller was in good shape, they're cleaning up the one tiny nick, and replacing the wear-ring which had a deep groove from the stone that was caught... I'm getting out of this one lucky.

Lesson learned.

 

[MooF]

wear ring pic

btw, here's the wear ring that was replaced: notice the grooves from the rock that was lodged in the impeller... $70 for wear ring, 1.5 hrs labor to repair impeller nicks.

 

[SeadooBOB Square Pants]

That is a great picture, thanks for sharing that helps the rest of us see the real deal.