Wear ring and impeller clearance

[mrclean667]

I just got my new motor put back in my 96 challenger. took it to the our local seadoo shop to make sure I did everything correct. Also had them replace the wear ring. I asked them about the tollerances for clearance. They said that as long as the leading edge is within specs <.10 (I believe is correct) that it should not cavitate. But I asked if there is a greater clearance mid blade that that is ok??!! they said sure

just want to get other opinions.

I have never had this boat working correctly in the 2 years I've owned it. Call me stupid for dumpin money into this thing, but I think it's cool and want to see life come back to it.

Friday will be my come to Jesus meeting with the lake, the boat, and me!!

if this doesn't do the trick then I will bring it back, re-seal the pump shoe and look into a new impeller.

I have replaced and redone everything else to this thing, the whole motor and pump (minus impeller) is brand new.

Can anyone think of anything else I can do to this thing before it gets parted out??

Thanks for all you knowledge!!

Jason

 

[Dr Honda]

The max allowable clearance is 0.040". Anything more than that... you will have bad cavitation. A good impeller, and an OEM SeaDoo wear ring will have almost no clearance when new.

Most of the time... if you have bad cavitation... it's coming from a leak in the carbon seal.

Regardless... go take it out for a ride, and let us know how it goes.

 

[mrclean667]

what is a good way to check to see if the carbon ring needs replacing??

As far as the clearance, should the clearance be uniform along the entire edge of the impeller? Like I said the leading edge was right up on it, but the center looked like it had more space between it and the wear ring. And I thought I read somewhere that you need to look at it from the nozzle (venturi) side. I looked at it from the the intake side just after the new wear ring was installed.

I think I will cry or have a really deep moment when this boat actually hooks up and works. My Fiance is about to kill me with this thing!! :stupid:

 

[phough5757]

I agree with Doc. You should have replaced the carbon seal when the Pump was out.
Good luck and keep Us posted.

 

[Dr Honda]

From the outside... it's hard to tell if your carbon ring is warn. (unless it's broken) The problem is... it can be warn uneven... or the boot holding pressure on it can be getting soft.

BUT... you can try one thing. Pull the carbon ring away from the stanless ring... and put a small blob of grease on the face of the ring. The grease will help seal it up. If the cavitation goes away (or is greatly reduced) then it's time for a carbon seal rebuild.


One thing... on some boats, the driveshaft has 2 or 3 clip locations. if your's has this... you can move the stainless ring up, and put more tension on the seal.

I'll post a few pics to help you check your seal for the extra clip slots.

 

[cli55er]

doc....thanks for all the help you give around here!

 

[Dr Honda]

doc....thanks for all the help you give around here!

:thumbsup:

I'm not always right... but I try.

 

[mrclean667]

I was finally able to get the boat to plane for the first time in 2 years of owning the boat!! It still cavitated on hole shot taking a few a bit to plane but was able to go through 2 tanka of gas to break in the new motor!! I am gonna buy a new skat trak 14.5/22.5 impeller, new carbon ring, and re-seal the pump shoe in hopes of making the hole shot cavitation go away!! After that I the whole back end will be freaking brand new. Won't know else to do after that!!

I could not have done it without all the help of Dr.Honda, Snipe, tommyboy, Karl, and so many others. I appreciate the time you all take on here and the knowledge you all give freely to those of us starting out with the older seadoo boats!!

 

[Dr Honda]

If you do that... you should be able to mash the throttle, and have it jump like a jetski.

And... No prob. That's what we're here for.

 

[95sportster]

From the outside... it's hard to tell if your carbon ring is warn. (unless it's broken) The problem is... it can be warn uneven... or the boot holding pressure on it can be getting soft.

BUT... you can try one thing. Pull the carbon ring away from the stanless ring... and put a small blob of grease on the face of the ring. The grease will help seal it up. If the cavitation goes away (or is greatly reduced) then it's time for a carbon seal rebuild.


One thing... on some boats, the driveshaft has 2 or 3 clip locations. if your's has this... you can move the stainless ring up, and put more tension on the seal.

I'll post a few pics to help you check your seal for the extra clip slots.

Just curious because of the corrugated rubber boot on the carbon seals. Mine is a straight piece of rubber tubing and that is what the parts diagram shows as well. Did your boat have the corrugated boot originally or is mine wrong? Getting ready to rebuild the pump and driveline seals and could replace it if necessary.

 

[parrothd]

95? I doubt you have a carbon ring setup like pictured above, you have a straight hose with a carrier bearing setup, much better..

 

[Smokymance]

Do all skis have that cover pictured on the first pics? I dont seem to have that!

 

[Stevego]

I think they are supposed to have it. But mine does not have it either.

 

[Smokymance]

Correct me if im wrong, but doesn't seem like to be a sealed cover rather than a protector kind of cover from stuff hitting or laying against the moving shaft

 

[Stevego]

I think it is also there to prevent the grease from splatting all over should the shaft boot ever split open.

 

[Smokymance]

Iv read around regarding cativation, but havent gotten a clear explanation on it. how do you tell weather your machine is cativating or not?