Severe cavitation after a trip to the coast!

[bell99man]

Ok, so all this time I have heard people talk about cavitation but I never really experienced it until this past week. On the first outing we went to the point of the peninsula and tried beaching the GTI's in an inlet but did not go far enough into it. One of them had started and I later found the fried carbon ring. Anyway, they got sideways and got sand in everything. I pulled them out to waist deep and we ran then into calm water and parked them. They ran fine on the way back with the one acting sluggish at take off or low speeds. Next outing we ran towards the shallow end of the bay and I led us several hundred yards into knee deep water with sea grass. We stopped but idled towards deeper water. By the time we found deep water, both were really slow to plane, like 30+ sec. So both skis were down for the rest of the trip. I pulled both pumps and took these pics of them. Is this that bad or are both carbon rings shot? One is for sure and I'll get pics of the other tomorrow.


I don't know if it will show up but the only wear appears to be on one side, the right side. It looks like torque caused the impeller to brush against the wear ring. Is this odd as it happened on both? Is it possible that the aftermarket wear ring flexed inward? I have a cou[le more pics if it might help.

 

[LouDoo]

The wear ring looks O.K., how much space is between the impeller and the wear ring? It should be no more than .025" about the thickness of a dime. Can you get a picture of the carbon seal?

Is your wear ring a SBT?

Lou

 

[bell99man]

Yep, they are from SBT. Nick says they are the problem. I've had them in since last season without trouble. I'll get a few more pics up this afternoon, work calls...

 

[bell99man]

Sorry I took so long to work on this but it rained cats and dogs for 2-3 days here. Anyway, I shot a pic of the carbon seal out of the machine. The little chips on the outer edge came from me dropping it on the driveway as I was removing it.



Does this look ok? It does to me but I haven't had this trouble before.

 

[Strizzo]

Carbon ring looks a little scored and that looks like heat marks on the stainless ring, iis there a groove in the stainless ring near the center? That may be the reason. I'd replace all of it while its apart to be sure, looks suspect all around.

 

[bell99man]

No grooves at all, but I thought the marks were odd. I probably ran it on the hose too long. Nick is sending me new carbon rings.

 

[Coastiejoe]

Make sure your motor mounts are all good. If only one side of the wear ring is damaged and you know the impeller and bearings/carbon seal are good, mounts can be the issue.

 

[bell99man]

Yeah, I keep grabbing the head and the big bend and shaking on it but it doesn't budge. I'll try grabbing the pto while the shaft is out.

 

[get_real]

The scoring on the one side of the wear ring looks pretty bad. I'm no expert but did stay at a Holiday Inn last night! Just kidding.... I did rebuild the pump on my GTI.

My advice would be to get the engine alignment checked while you have the pump housing off to ensure the driveshaft angle is correct. If it's off quite a bit that could be the problem with both the wear ring damage and how the carbon seal functions. You could either buy or rent an alingment tool, or take them to a shop. My local shop said they'd only charge around 1/2 hour labor to align the motor if the pump was off. I'd buy a shim kit first and take it with me, my shop had no shims in stock.

I'd also check to see if there is any problem with the impleller shaft & bearings especially if you replace the wear rings.

 

[SabrToothSqrl]

* Holiday Inn Express.

 

[get_real]

* Holiday Inn Express.

I stand corrected....Holiday Inn Express! I'm too cheap for the Inn!

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[bell99man]

I like the Express, nice kitchenettes in the Nashville and Atlanta\Decatur locations(company training trips).

As far as I can tell, the motors have not been out before but I don't know for sure. It has never leaked or cavitated before now. I suppose it could slowly walk out of alignment if the mounts were loose or broken but they seem really snug.

 

[get_real]

With a ski that old its very possible its out of alignment. Mine was off over 1/4".

I'm 1 1/2 hours from Decatur. Lets meet for a beer next time you come!
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[bell99man]

If you have the tool I will take you up on that.

 

[get_real]

No....I had the dealer check mine. Since he didn't have the correct shims didn't charge me a dime but told me how much to shim it.

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[bell99man]

Man, where do you ride? I was looking at Google maps and you have very little water around you. I see Houston Lake and a couple others together but they look kinda small.

 

[bell99man]

Ok, I finally got a chance to remove the other carbon ring and carrier. Here is a shot of the carbon ring. Do you think this is just from heat?

 

[bell99man]

Just to update, I replaced the carbon seal on one of them and put the OEM wear ring back in the other and went for a test ride with my neighbor and his wife. We had a great time and they ran like they never had a problem! They took 4-6 spills and were laughing and loved it. The guy has been out with me before so I knew his riding style. All in all it was beautiful dusk ride with some fantastic neighbors! Can't wait to do it again.


Moral of this story, when these guys say "don't run it on the hose for very long," this is why. BECAUSE it is expensive and time consuming to replace parts. Seriously, find a way to keep this thing cool. Thanks to all and hopefully my hard head is a little smarter now.

 

[get_real]

Man, where do you ride? I was looking at Google maps and you have very little water around you. I see Houston Lake and a couple others together but they look kinda small.

Glad you got your problem solved. Will be interested to see how the new wear ring holds up.

I ride mostly on Lake Sinclair and Lake Tobosofkee. Both nice lakes but a little choppy on the weekends due to all the boat traffic. I have my RV on Sinclair for 3-4 months in the summer. In fact I'm there right now and the XP is in the water!

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[bell99man]

Glad you got your problem solved. Will be interested to see how the new wear ring holds up.

I ride mostly on Lake Sinclair and Lake Tobosofkee. Both nice lakes but a little choppy on the weekends due to all the boat traffic. I have my RV on Sinclair for 3-4 months in the summer. In fact I'm there right now and the XP is in the water!

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Nice, I've been trying to find a spot for my RV on Lay Lake here but it's tough because of the limited number of spots. We rode again today. Still pulling good but with 2 on and a knee boarder, she has a little trouble out of the hole but just a little. I think my oldest kid will never get on another towable, well, maybe a tube. My youngest will try most anything wet.

 

[get_real]

Where is lake May? The RV park here is great....you can reserve sites right on the lake and its only $495 a month with all utilities including cable & wifi. Lots of folks keep spots all year...1/2 price in winter.

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