I知 cavitating at take off and at full throttle.

[wallacemerritt]

I read through other posts on this topic and I'm trying to narrow my problem down. I have a 92 GTS that I just bought and while throttling up to come on plan it will cavitate unless I easy the throttle on. I mean easy it on. If I pull the throttle to fast it will just cavitate and go no wear. Also if I open it up all the way after on plan it will cavitate. I just got under the ski and pulled the intake grate off and looked everything over. There is maybe enough room to slide a peice of paper all the way around the impeller and wear ring. The clearenss seems to be very minamal. From looking at the impeller it donsn't seem to be in that bad of shape to me. There's one small ding that is very small so a can't imagine that being my problem. The cavitation is pretty bad. I did read that someone said something about sealing the pump house to the shoe. Are they calling the ride plate the shoe? I'm just trying to clearify. I have a break down of the pump that I'm looking at. Any ideas were or what I should be looking for? It's getting close to the end of riding season and I want to get this thing out and play some more before it's to cold. Thanks

[TX21]

Re: I知 cavitating at take off and at full throttle.

Are you sure its cavitation?

[Bill O'Neal2]

Re: I知 cavitating at take off and at full throttle.

It is not always easy to see damage to a wear ring or impellor when it is still in the ski. Pull the pump.

The reason I say pull the pump is because if it isn't a wear ring or impellor problem, it will be the sealant between the pump and the pump support plate.
Rarely does your model need the shoe resealed to the hull, unlike 1996 and later models that use a plastic shoe.

[wallacemerritt]

Re: I知 cavitating at take off and at full throttle.

I'm pretty sure. If i pull the the throttle in to fast, the rpm's just shoot up and it goes no were and it kind of sounds a little like a blender under the ski. What are you thinking?

[wallacemerritt]

Re: I知 cavitating at take off and at full throttle.

Thanks Bill, I was kind of hoping you would chime in. I plan to pull the pump this evening. What exactly should I be looking for?

[TX21]

Re: I知 cavitating at take off and at full throttle.

I'm pretty sure. If i pull the the throttle in to fast, the rpm's just shoot up and it goes no were and it kind of sounds a little like a blender under the ski. What are you thinking?

Well after hearing that sounds like you are looking in the right direction.

[Bill O'Neal2]

Re: I知 cavitating at take off and at full throttle.

Typically, you will find a bent impellor. It is the back side blades that get bent when a rock gets caught between the blade and the vien in the pump. Also, wear rings can have chunks missing, or just be too worn out.

The pump should be stuck to the pump support plate with a bunch of silicone to seal it to the pump support plate. It should be difficult to pull out, close to impossible without a pump puller.

[wallacemerritt]

Re: I知 cavitating at take off and at full throttle.

I will attempt to pull it with out the puller and see how it goes. If it comes off easy then that may be my problem. Maybe the sealer is shot. I will post my findings.

[JOECBRZX]

Re: I知 cavitating at take off and at full throttle.

Get Rid Of That Piece Junk!

[wallacemerritt]

Re: I知 cavitating at take off and at full throttle.

That's funny becuase this piece of junk had to tow that broken down blaster back to the ramp this weekend. A little routine maintenance will keep those bearings from going out. LOL

[wallacemerritt]

Re: I知 cavitating at take off and at full throttle.

I pulled the pump and the impeller looks fine from what I can tell. There are no major dings only very, very minor spots. I mean real minor. Anyway I took some sand paper and smoothed the edges of the impeller out just to give it a nice sharp edge. I replaced the wear ring and after spinning it a few time I noticed that the impeller was rubbing a little against the new wear ring. I spoke to BILL at watercraft magic and he said that it happens and to spray some WD-40 in there and let the impeller cut the new wear ring to fit. When I took the pump off there was no sealant between the pump and the shoe. There was only a foam type ring. From what I have gathered the best thing to do is reseal it with ultra black and not use the foam ring. Is this correct and am I putting the sealant were the foam ring was? Thanks for all the help. Hopefully this will fix my problem.

[Bill O'Neal2]

Re: I知 cavitating at take off and at full throttle.

Use one or the other not both.

[wallacemerritt]

Re: I知 cavitating at take off and at full throttle.

OK just an Update. I replaced the wear ring and resealed the pump to the shoe. I took the ski out for a test run and every thing works great. It pulls like a freight train. Thanks for every ones input.