Cavitation

[Michael Cain]

Greeting All,

Last weekend I purchased a 96 seadoo speedster. Unfortunately, it's cavitating so bad that it will not even plain out- it just revs high when I accelerate past a certain point. I've look at the propeller to ring clearance and it looks tight. I assume its sucking air from the boot or something? I plan on working on it tomorrow. Where to start?

Thanks,
Michael

 

[Dr Honda]

It's probably sucking air in around the carbon seals. Try this... pull them back a little, and put a blob of water proof grease on the face of the seal. If it works... order some new carbon rings, O-rings, and boots.

If it doesn't work... look for a leak around the pump, where is meets the ride shoe.

 

[Michael Cain]

Will do. Thanks!!

 

[Michael Cain]

I pushed the boots back and packet them with grease. Took it to the water and still cavitates so bad that it won't plain out. One side it leaking water at the smaller end of the accordian where it slides against the steel, stationary piece.

 

[Phildoo]

He was saying to put a small amount between what you call the stationary piece. Not pack the boot with grease.

 

[Michael Cain]

He was saying to put a small amount between what you call the stationary piece. Not pack the boot with grease.

That's what I did.

 

[Michael Cain]

Oh I see, I called my brother to post for me. Lol I just slid the boot back and put grease where the two surfaces meet.

Mc

 

[Phildoo]

Gotcha.. Like dr Honda said, probably gonna need new carbon seals but did you check out the ride plate?

 

[Dr Honda]

The boat in my Avatar was the same way when I bought it. Because it was SO bad... I decided I was only doing it once.

If you don't know exactly where the leak is... just pull it all apart (The pump, ride shoe, drive shaft) and re-seal all of it as you put it back on the boat.

If you can see a physical water leak... that will be your problem. Normally, a carbon seal will allow air into the pump... but will still seal the water out.

 

[Michael Cain]

Honda,

Thanks for all of your help. When it's cavitating and revving high in the water, water is squirting in between the carbon seal and the metal surface that it rides on. So I assume I should order new carbon rings and o-rings? Should I order new boots (The ones on it are in good shape). Do you recommend a place for me to purchase these items?

 

[pincusa]

I would order new everything. Boot, seal, O rings, and SS collar.
Though the rubber boot looks OK, it's what's putting pressure on the carbon seal. As it get old, it becomes stiff and won't move as it should. Another trick you can do is slid the boot maybe 1/4-3/8" forward to compress it and put more pressure on the seal. Don't slide it more that 1/2" or so or you'll be out of room to bit on the Fglass tube that it seals against.