same problem!!!

Ok, here's the problem:

1997 SJ is STILL porpoising badly. Had an Aluminum pole and thought it was maybe too long or the wrong pole (we thought it may be an Octane pole)... NOT THE CASE. I just put on an x-metal pole, a -2, which measured out the same as the aluminum pole that was on the ski. Although I did install the x-metal without the shortened plate (just for comparison sake), I was still hoping this would help, but it didn't.

There is also cavitation and a very noticeable vibrationa associated with engine speed in the rear of the ski... related perhaps?

I've been told to take the pump down and check for the pump seal... what else should I check?

Any ideas?

Thanks,
Brad
 
what plate on there..?

It's a Riva extended.... not cut.. extends past hull about 2 1/2 inches. Also, when I originally got the ski, the plate was shimmed... but I removed the shim. I've ridden other SJ's and none react like this, even stock ones don't porpoise like mine... It seems to be throttle related. I think there's just a tweek somewhere.... could a pump seal or something cause this?
 

waterfreak

I had a vision!
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Check your intermediate bearing housing (the one bolted to the firewall!) Sometimes, the rubber breaks away from the housing and the pump sucks air from the engine compartment causing cavitation. Of course, make sure everything in the pump area is ok
 
Brad,

Lets ride this weekend and we'll see if we can figure this thing out.

Let me know. I sold my ticket to the game so I can ride Saturday or Sunday.

Dan
 
Check your intermediate bearing housing (the one bolted to the firewall!) Sometimes, the rubber breaks away from the housing and the pump sucks air from the engine compartment causing cavitation. Of course, make sure everything in the pump area is ok

I'll check the intermediate housing... what should I be looking for in the pump area to make sure everything is ok?

I really want to solve this problem!
 

waterfreak

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I'll check the intermediate housing... what should I be looking for in the pump area to make sure everything is ok?

I really want to solve this problem!

Check the big rubber o-ring on the back of the pump and make sure it seals the pump to the ride shoe. Also, check the clearance between the prop and the liner and finally , inspect you pump shaft .
 
Check the big rubber o-ring on the back of the pump and make sure it seals the pump to the ride shoe. Also, check the clearance between the prop and the liner and finally , inspect you pump shaft .

Thanks! I'll check it out.


FLY6584 said:
Brad,

Lets ride this weekend and we'll see if we can figure this thing out.

Let me know. I sold my ticket to the game so I can ride Saturday or Sunday.

Dan

Probably can ride Sunday, def not Sat though... your right, I want to figure this out!!
 
Check the big rubber o-ring on the back of the pump and make sure it seals the pump to the ride shoe. Also, check the clearance between the prop and the liner and finally , inspect you pump shaft .

What should the clearance for the prop/liner be?

Any other ideas that could cause the problems with porpoising??
 
Ok, I've taken the pump out... there were no shims on the rear, although the manual says there are shims (at least one on the starboard side).

The prop seems to have correct clearance and no damage is visible on the prop or the pump housing.

The pump shoe does have a chip out of it, but I don't see that it could effect performance; could it?

The large O-ring between the pump and the pump shoe seems to be intact and alright.

I do NOT know how to check on the Mid-Shaft Bearing... Can anyone tell me how to inspect it without pulling it out?

Here are some pics. ANY ADVICE WOULD BE HELPFUL!!!

Thanks!
Brad

thumb_DSCF0300.JPG
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thumb_DSCF0274.JPG
thumb_DSCF0298.JPG
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thumb_DSCF0277.JPG
 
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How come you can't ride Saturday? I think thats the day we're gonna ride.

I don't want to hear because of the Auburn vs Arkansas game. Its gonna be another blowout. Heck I still go to school here and I'm not even going. It must be an Alumni thing. :biggrin:
 

SUPERTUNE

Race Gas Rules
Location
Clearwater Fl.
There's no way that will NOT cavitate! Get to work and put in a new one. It's no fun but you got to do it!
I keep them in stock, so does that tell you this is very common...
 

crammit442

makin' legs
Location
here
There's no way that will NOT cavitate! Get to work and put in a new one. It's no fun but you got to do it!
I keep them in stock, so does that tell you this is very common...

He's right about that! I've got a used stock shoe you can have.(not damaged). Holler at me!

Charles
 
There's no way that will NOT cavitate! Get to work and put in a new one. It's no fun but you got to do it!
I keep them in stock, so does that tell you this is very common...

Thanks for the information! I had no idea such a tiny chip could cause problems.

crammit442 said:
He's right about that! I've got a used stock shoe you can have.(not damaged). Holler at me!

Charles

Let me know, I obviously need one!
 
every ski is different, one person may have 2 shims, another none.....another 1 shim.........etc etc

I may try a shim and see if that helps... I'll be careful to check shaft alignment... also any way to inspect the mid-shaft bearing w/o removing it?

Thanks again!
 
listen to whatever supertune tells you, he knows. If he says it, I just do it,no questions asked (its not necassary)
 
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