96 XPS cavitation

[mando]

Great site, with all the information here I've rebuilt the carbs, replaced all the fuel lines and throttle cable that my buddy broke when he snapped the handle bar. Now the engine runs fine, but I have no bottom end, it plows until it planes, then it goes great. I took the pump off and the clearance from the blades to the wear ring is .229 mm. With the cone shaped housing cover removed, but the impeller still in place, the shaft moves back and forth about 1/4". I'm enclosing a couple pictures of the impeller. Any suggestions on where to check next or if the impeller looks bad would be appreciated. This is my first jet ski....

 

[LouDoo]

Hi and welcome to the SeaDoo forum,

Sorry, I don't know what the metric conversion is but the clearance between the impeller and the wear ring should be no more than .040", about the thickness of a dime. 1/4" back and forth movement sound a little high, I don't know what the exact specs are but about 1/8" to about 3/16" sound about right.

Looking at your second picture at the extreme edge of the pic. it kinda looks like the wear ring is starting to delaminate, I can't tell for sure. The impeller looks in pretty good shape you can take the small nicks out with a dremel or a file.

Lou

 

[skewba98z28]

How was the neoprene seal between the hull and the pump? Your wear ring clearance doesn't look that bad visually. I would try a new seal and be sure to silicone around the bailer lines and try it again. Put some marine grease on the impeller splines where the drive shaft goes in. That nick in the impeller is not good for optimal performance, but it shouldn't make the pump cavitate.

 

[ltdyfz99]

Get a new neoprene seal no matter what now since you removed your pump, Also check the hull through fitting, and your drive shaft seal either one could be letting air in as they loose the the strength over time quick trick is to you a hose clamp to move it forward to seal that carbon ring up if its worn. How is your carbon ring?

 

[Minnetonka4me]

Yup try the easy stuff above...

Worst case is the ride plate needs to come off and be reglued....not a real fun job.

 

[mando]

Thanks everyone. I will do as suggested. Now that I know what and where the carbon ring is, and how it supposed to work, I'll inspect it this weekend. I'm assuming it wears out with age? The neoprene seal was intact, I will replace it along with all the o-rings.
Thanks again for all the input.

 

[andrewterri]

If you use silicone to reseal the pump make sure you wait two or three days to let it dry or you will blow out all the silicone you just put on. ** Dont ask me how I know :thumbsup: its okay I really wanted to do it twice anyways

 

[mando]

No time to work on the ski, but I took a couple of pics. How "bad" does that hull crack look to you guys? I'll take the shaft and other bits off next weekend.

 

[spx800]

this ski is in ruff shape. In my mind that crack is bad and i would get it repaired asap.

 

[LouDoo]

:agree: It looks like in the second picture that there might be additional structural damage above and to the left of the bolt.

Lou

 

[mando]

"It's just a flesh wound"

 

[skewba98z28]

Ouch man!! In a rough spot to fix also. At least you really won't have to worry about what it looks like after you fix it because nobody will see it there

 

[Dr Honda]

Does the pump stud move? Can you wiggle it, and see the fiberglass move? Personally, from my end... it could be superficial.

Also... from my end... I can tell you that your cavitation is going to be at your carbon seal. First... if you have rust on the stainless ring... it's pitted, and going to let air past. Second... since I can see rust behind the ring... I'm going to say the O-rings inside the Stainless ring have split. And finally... since there isn't a clamp on the boot, at the carbon ring... it's sucking air past.

To have cavitation to the point that you are talking about... it takes an air leak. Besides... your pump clearance looks ok from the pics.

 

[nikko_m]

is there a way to fix those problems?a new hull would be way too much.

 

[Dr Honda]

is there a way to fix those problems?a new hull would be way too much.

A hull is normally almost free. Guys like Minnitonka... who strip seadoo's for the parts, normally have to pay to dispose of the hulls.

 

[LouDoo]

If it's not a structural repair. If the stud doesn't wiggle and the pump mounting area is solid, I've had good luck with Locktite Marine Epoxy, Lowes has it. If it's a structural repair I would have a professional look at it.

Lou

 

[Strizzo]

your wear ring looks ok on one side, but to the right side of your first picture, you can see where the impeller has scraped on the rubber. this is probably due to the side to side play you mentioned. the service manual says max allowable side to side play spec is .002" or .05mm. if this is out of spec, you will need to inspect further, as the bearings and/or shaft could be worn out. check the shaft diameter both where the bearings ride and check for grooves where the seal rides. the shaft minimum diameter per the manual is 22.24mm. my new replacement shaft was only 22.25mm so there is not much room for wear. the manual says that the shaft should be replaced if there are grooves from the seals, but most people don't unless there is scoring that would damage the new seal.

Dr. Honda sells a pair of tools that you can use to remove the bearings and old seal and properly seat the new parts in the pump housing. pm minnetonka4me for a good used carbon ring and floating ring, then i'd replace the o-rings in the floating ring with new ones unless the used ones look brand new.

 

[LouDoo]

:agree: I guess that's what I was trying to say in post #2, but it also is causing the wear ring to de-laminate, see picture 2. on the extreme right.

Lou

 

[Strizzo]

:agree: I guess that's what I was trying to say in post #2, but it also is causing the wear ring to de-laminate, see picture 2. on the extreme right.

Lou

:cheers:

also, the pitting on the impeller looks really bad, but its just a result of someone running it with the cavitation issue like that for a long time, and now surface rust has set in. you could probably clean up the leading edge of the impeller, and clean up the rust with some steel wool, or if there is other damage, SBT has an impeller exchange where they take your old one and send you a re-worked factory one for around 65 bucks plus shipping. i didn't know about that when i did mine and ended up buying a new solas concord

 

[mando]

Ouch man!! In a rough spot to fix also. At least you really won't have to worry about what it looks like after you fix it because nobody will see it there

My thoughts exactly!

 

[mando]

Does the pump stud move? Can you wiggle it, and see the fiberglass move? Personally, from my end... it could be superficial.

Also... from my end... I can tell you that your cavitation is going to be at your carbon seal. First... if you have rust on the stainless ring... it's pitted, and going to let air past. Second... since I can see rust behind the ring... I'm going to say the O-rings inside the Stainless ring have split. And finally... since there isn't a clamp on the boot, at the carbon ring... it's sucking air past.

To have cavitation to the point that you are talking about... it takes an air leak. Besides... your pump clearance looks ok from the pics.

I'm pretty sure that stud was solid, I'll have another look soon.
Shopping list so far: carbon ring, 3 oil rings, front boot (cracked), water inlet fitting (i broke it).
I removed the forward clamp on the boot, it's barely visible in the pic.

Thanks for the help Dr. Honda.
PS We have Yammy's, Suk's and a '69 Husqvarna dirt bikes, just sold our only Honda, a CRF50F-best starter bike ever made...

 

[mando]

:cheers:

also, the pitting on the impeller looks really bad, but its just a result of someone running it with the cavitation issue like that for a long time, and now surface rust has set in. you could probably clean up the leading edge of the impeller, and clean up the rust with some steel wool, or if there is other damage, SBT has an impeller exchange where they take your old one and send you a re-worked factory one for around 65 bucks plus shipping. i didn't know about that when i did mine and ended up buying a new solas concord

The impeller cleaned up nicely. I think I'll keep it, but thanks for the info.

 

[mando]

I didn't mic the radial play. I meant to say the shaft was moving forward and back a bit more than I thought it should. My observation is of course totally ignorant, as I have never worked on a jet ski before. But now I read somewhere on this forum that SeaDoos are a little sloppy in this area and make a bit of noise? There seems to be a couple of parts missing inside the cone, item #12 and #29 on the diagram below. I would think they would reduce this play?

 

[Dr Honda]

On a seadoo... the "In and out" play in the pump is HUGE. There is only a thrust washer, and there is no way to "Load" the bearings. So... as long as the impeller doesn't go side to side... you are fine. As far as #12 and #29... not all the skis had the pusher installed. Personally... just leave it out if you don't have it. I've seen them melt, and cause problems. The worst thing that will happen, is if your idle is low... you will hear the pump knocking. (shaft moves back and forth) But... the pusher doesn't help much.

Also... I know the guys were saying something about the wear ring delamiatiing... but I wasn't seeing it. (I guess I may have missed something)


I was a Die-Hard Yami rider for about 15 years. (Racing SCORE in SoCal) But then they started to have issues that they weren't taking care of... so in 2005, I finally got fed up, and I traded in a 4 month old FZ6, on My Buell. That was the last Yami product I owned. (Other than my 91 Superjet, and EF600 generator) My "Dr Honda" is an old chat board name that I just decided to keep using. (From my import car days)

 

[Strizzo]

the radial play is a pretty small tolerance, that combined with the tight tolerance between new and max allowable on the shaft diameter, and anything more than "it barely moves" is out of spec. mine barely moved and it was like one thousandth under the max allowable.

the pats you're referring to weren't always installed, all they are supposed to do is keep a bit of tension against the thrust bearing to stop the "seadoo rattle" at idle, caused by the huge amount of end play that you noticed.