2005 RXP Pump Question

[Got Water?]

So I started having cavitation issues when I take off and decided to pull the pump and check it out. I took the impeller cover off and it was full of water. So I'm going to rebuild the pump with a new bearing, seals and wear ring. My question is that after removing the pump I was looking at the intake tunnel and noticed that some of the plastic guide vanes are broken. How necessary are these? I've seen some youtube videos of Seadoo's that don't have them at all. Is it acceptable to grind all these off or will it effect the performance of my ski? Could this have been causing my cavitation problems? Thanks for any help you may provide.

 

[AircraftDoc]

Check the leading edge on the impeller. Dented and flattened impeller is the main cause of cavitation.

Go ahead a pull the pump housing. Ref shop manual.

 

[Got Water?]

Yes it had some nicks and ruffness to it. Nothing major but a lot of minor. I've got it all cleaned up and looking good. I am having trouble getting the bearing out of the housing. Any suggestions?

 

[AircraftDoc]

Use your freezer. And spray penetrant.

 

[68ragtop]

My RXPX had broken fins in the water tunnel. I cut them all off & smoothened them out. I made a post about this a while back & I was told by another member they need to be either all in tact, or all taken out. I bought mine with broken fins, so I can't tell you if they cause cavitation, but I can tell you I have no hook up issue at all.

 

[Got Water?]

Awesome! Just what I wanted to hear. Thank You!

My other issue is getting the bearing out of the housing without the use of a press. I drove the shaft out but all it managed on doing is removing half the bearing race with it. The main bearing is still in the housing. Any tricks or tips?

 

[AircraftDoc]

Put the part in the freezer. It will probably pop out. You can also use spray freeze. A bench or stand up freezer. Or use your neighbor's if you don't have one.

 

[Got Water?]

I tried that. The wear ring popped right out. I took a couple wacks at the bearing and it was pretty solid. I'll try it again.

 

[AircraftDoc]

Let it sit awhile. Then try slow and little pressure. Hold pressure on it for a few minutes, don't push hard. You could try cool one part and heat the other. Work at it slowly.

 

[Got Water?]

Ok, I got everything put together and took it out today and still have cavitation on the bottom end. Can I assume the impeller is bad? I cleaned up all the edges and none of the blades looked bent? Everything else has been replaced. The only thing different is I removed those plastic fins prior to the impeller and added a riva intake grate. The wear ring is new as is all the bearings and seals. I did not measure clearances on it after the impeller was installed, figured it would be ok. Comments?

 

[red2blue]

Ok, I got everything put together and took it out today and still have cavitation on the bottom end. Can I assume the impeller is bad? I cleaned up all the edges and none of the blades looked bent? Everything else has been replaced. The only thing different is I removed those plastic fins prior to the impeller and added a riva intake grate. The wear ring is new as is all the bearings and seals. I did not measure clearances on it after the impeller was installed, figured it would be ok. Comments?

pics are a plus

 

[Got Water?]

What would you like pics of?

 

[red2blue]

heh...what you want our opinions of....

How about the prop? What kind of clearance do you currently have between the prop and ring?

Also...a lil history of the ski...parts ect.

 

[Got Water?]

Ok, if you read above you'll have read that the whole pump had been rebuilt minus an impeller. That means new bearing, wear ring and all new seals. Now I pulled the pump back out and the blade to ring clearance is sitting around .022 which is well below the max allowed of .035. I removed the impeller and took some pictures. It had some minor nicks which I blended out. I also cleaned up any burrs on the pump housing guide vanes. I'm not seeing anything wrong here, maybe someone on the forums does? Before it would pull nice and strong from a dead stop, now it feels like it's slipping until the speed builds up. The top end is still there at 70mph indicated.

 

[red2blue]

Where's the grate? who told you .035 was max acceptable?

Good range is .01-.015

Mine reads .004-.006 with a stainless ring.

Don't believe the dream-o-meter. Need to get a gps for decent accuracy.

What kinda r's are you seeing wot?

 

[Got Water?]

Intake grate: stock vs riva







The shop manual



The dream o meter works fine for comparison. I know it's not doing 70 mph.

 

[Got Water?]

Ok I see where I was reading mm not inches. .014 is max inches. So is the new wear ring bad or old impeller? There are no scuffs on the wear ring.

 

[red2blue]

Two thoughts here....

One....you're gonna go with the Riva? You'll have better hook-up in the chop....but grates are a drag and w/o more power it's gonna slow you a bit.

When you replaced the ring....did the prop scuff at all when you put it in? Most folks complain that it's too tight. When the motor fires the prop will "cut" into the ring a bit. That....is normal. If your's went in w/o touching at all...I'd say one of two things...either your prop's dia has been reduced or your ring is a bit thin.

Also if your gap is .022 I'd say one of the previous is the culprit.

 

[Got Water?]

No scuffing at all. I went back out and measured again. Near the bottom of the pump, on all blades I'm measuring a clearance of about .023 but near the top of the pump on any blade I'm measuring a clearance of about .009? So I'm going to press the bearing back out and see if it gathered some material on the way in the first time. If it was even that would give me an average clearance of .016, much closer to the max allowed. What are the chances of the impeller with 60 hrs on it wearing down versus and undersized wear ring?

 

[red2blue]

Right off hand...you shouldn't have that kind of discrepancy from one side to the other.

If it was me I'd look at the ring being the prob. Unless you took a file to the outside edges of the prop...it don't sound like you did. Sounds like one...ring was bad.....bearings aren't seated properly....or pump is warped.

 

[Got Water?]

Right. Thanks for the help.

 

[Coastiejoe]

Shake the engine as well, make sure you don't have a motor mount issue.

The thickness of a dime is an acceptable gap, more than that and it is too much. The .010 is where you should be, not larger.

If you roll the impeller 180 degrees does the gap stay the same or does it move around with the impeller?

 

[Got Water?]

The gap stays the same, larger gap is at the bottom and smaller at the top regardless of blade position. I will check the motor when I get home.

 

[Coastiejoe]

Well. If the bearings and pump and wear ring are installed correctly. You need to look hard at the motor mounts. Even if they are good. You will need to align the engine.


Repairing and selling iPads, iPhones and Mini iPads.

 

[Got Water?]

I don't understand. The engine and the pump are separate units joined only by a shaft that is splined and floats inside the impeller. It has no hard mounting to the impeller whatsoever.