2005 RXP Pump Question

[Tytan]

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.

If the alignment is out then the carbon ring and collar will not line up correctly, the contact area is then off center and the seal is easily broken under hard acceleration which will cause air to be drawn into the pump tunnel which is a cause of cavitation. If a motor mount is bad the engine can move too much under load forcing the driveshaft out of alignment and causing the same problem.

What is the condition of the carbon ring, collar and accordion boot ?

Clean up the trailing edges of the impeller as well put the impeller fat hub down on a flat surface and make sure the trailing edges are all straight and equal distance off the flat surface.

It's a good idea to replace the accordion boot and carbon ring every few years as the boot weakens with age and will not apply adequate pressure on the carbon ring. Carbon rings wear over time they can wear in odd patterns especially if the alignment is out or you have a bad motor mount. Plus a carbon ring failure can sink your ski very quickly. I will replace the boot, carbon ring and driveshaft C clip every two to three years as preventative maintanance.

 

[Got Water?]

Ok interesting. I will look into it for sure. I'm at work so I won't be able to look at anything until tomorrow.

 

[Got Water?]

So does the driveshaft need to be removed to replace the carbon ring? Or can I inspect it by removing the clamps on the accordion boot? I just went for a 100 mile ride yesterday and had no water in my hull. Can I assume the carbon ring and boot are doing there job?

 

[Got Water?]

The manual calls out a PTO assy? Is this the carbon ring you speak of?

 

[Tytan]

Driveshaft needs to be removed to replace the accordion boot and carbon ring.

PTO assembly is a rubber boot with a bearing in it that is clamped to the rear of the engine. This driveshaft is removed from the bearing and the bearing and boot assembly will stay attached to the engine. It's a good idea to have a shop manual handy the first time you take this apart.

Access to this area is a lot easier with the supercharger removed, not required just makes it sooo much easier.

 

[Got Water?]

Ok, so I discovered that the new wear ring I installed was defective. Wall thickness was different 180 degrees apart. .191 to .223. So I've already installed a new wear ring and got .009-.011 all the way around. Checked the engine out and appears to be secure. Since I have no water intrusion into the hull I will save the carbon ring project for another day. Took it out and it still does not feel like it used too. On an early GoPro video I see that the rpm's jump to just under 8000 rpm and at about 20mph it settles down to 7500 rpm and slowly rises to about 7800 rpm at top speed. Maybe someone can tell me if this is normal for a stock ski. Now it jumps to about 8200 rpm when I launch and the settles down to 7500 rpm at about 20 mph. And this whole process feels like it take longer. This test was done with the Riva intake and stock intake, no difference noted on launch. I might have a video of this but will have to search for it. Here is the way it used to be video.

[video=youtube_share;gtIqNjrxQdM]http://youtu.be/gtIqNjrxQdM[/video]

So I can think of only two things it can be at this point.

1) Impeller is bad?

2) Those guide vanes I removed in the intake just before the impeller is causing the problem?

I have ordered a new Solas Concord impeller and will install it next week.

Thanks for the help.

 

[red2blue]

...This test was done with the Riva intake and stock intake, no difference noted on launch.

So I can think of only two things it can be at this point.

1) Impeller is bad?

2) Those guide vanes I removed in the intake just before the impeller is causing the problem?

I have ordered a new Solas Concord impeller and will install it next week.

Thanks for the help.

The grate is gonna be a bigger drag than the oem...

need to open up that air intake...

What's your oil level sitting at?

Fuel level?...

Air and water temps when comparing results...

Finally...what was your trim set at?

 

[Got Water?]

Red2Blue thank you for your input but most of what your asking is irrelevant other than the trim setting which is all the way down at launch and driven all the way up after it planes. It was working fine until a couple weeks ago when I got stupid and went where I shouldn't have and sucked some crap into the pump several times. Immediately afterwards is when the cavitation started. So my issue is directly related to the pump. I'm just trying to pin down what. As I said in a previous post:

I can think of only two things it can be at this point.

1) Impeller is bad?

2) Those guide vanes I removed in the intake just before the impeller is causing the problem?

I have ordered a new Solas Concord impeller and will install it next week.

 

[red2blue]

Red2Blue thank you for your input but most of what your asking is irrelevant other than the trim setting which is all the way down at launch and driven all the way up after it planes. It was working fine until a couple weeks ago when I got stupid and went where I shouldn't have and sucked some crap into the pump several times. Immediately afterwards is when the cavitation started. So my issue is directly related to the pump. I'm just trying to pin down what. As I said in a previous post:

I can think of only two things it can be at this point.

1) Impeller is bad?

2) Those guide vanes I removed in the intake just before the impeller is causing the problem?

I have ordered a new Solas Concord impeller and will install it next week.

Cool....I somehow was under the impression that you were simultaneously installing mods as well as chasing down a cavitation prob and missing rpms.

Full down on launch is cool...but 1 above neutral will net you the best numbers up top.

Doubt it's the cleanly removed sharks teeth before your prop. Many have removed them completely with no degradation of performance.

 

[Got Water?]

Ok I replaced the impeller and everything works perfect! Took on a GTR today and blew him away! I'm happy! RPM's hit 7500 rpm at launch so the pump is loading from the get go! Thanks to everyone for there help and advise!!