97 Gti can't pull a skier

[kswiatk]

I am having continually issues with cavitation or ventilation on my 1997 gti. It used to cavitate under full acceleration so I did the following. It also struggled to pull a waterskier or wakeboarder up.

Previous owner had put an older style carrier bearing/seals in there, so I replaced with a carbon ring. No Change in performance. All bumpers and grease used in pto to push the shaft back.

Replaced wear ring with OEM seadoo and pump plate seal. No change

While doing wear ring I noticed the metal hub in the plastic pump was loose and knocking back and forth. So replaced with a brass pump. No change

Removed pump shoe (deflector) and resealed. Slight improvement.

The cavitation when accelerating during riding is still slightly there, I can't feel it but can hear the rpm lower slightly during acceleration. It still revs up completely when trying to pull a skier up, but a more experienced rider can get up eventually .

My 94 sp with a 580 has no problem pulling up a skier however it has a solas impeller.

I am unsure where else to look at this point. The impeller has some very small knicks on it but is in fairly good condition.
Anything else to look at before I consider an impeller or is it in the nature of this machine.
Thanks for any help.

 

[glsmohio]

Do you have the correct prop?

 

[kswiatk]

according to the manual yes

 

[mikidymac]

Keep in mind this is a 3 seater with only a 85HP 720 they don't have a ton of power. It sounds like you have covered all of the usual suspects that would cause more than normal cavitation.

 

[kswiatk]

I was thinking that, but it just seems weird to me that with any drag in the back it will rev all the way up and barely move, considering the weaker sp doesn't.
I have also been having the same issue on my 96 gsx 787, but it needs a new boot for the carbon ring before thats definitive.

 

[dieselndoo]

Post pic of impellor/wear ring gap

 

[kswiatk]

I will post a picture tomorrow once i get get the pump pulled.. However, there was nothing notable earlier. The wear ring clearance was about .25mm all around after install.

 

[Mekanix]

Your 580 is geared so to speak for low end pulling power. The gti had more power but is geared towards getting 3 people going at a decent speed and not really for pulling.
If you want more pulling power you will have to change the impeller. Or go with a solas/ skattrac. You would loose some top end but gain lots of bottom end. Every 97 gti I've worked on and ridden has never been able to pull a skier out of the water. Off the dock maybe sometimes and while at speed but it really doesn't have the low end without feeling like its cavitating.

If you can find a 2000 gs big cone pump that would help with low end pull.

What you are describing is exactly what I've felt on many machines before and after 96. Seems like they changed allot with the newer hull design.

I wonder if just a reduction in nozzle size would make a difference.

I noticed that my 2000 gs had the big cone pump and a longer smaller nozzle and it would stay hooked up much better on low end. But when i switched to a 97 gtx bronze pump and come and a gti impeller it would seem to unload the impeller on low end and feel like its cavitating instead of hooking up.

 

[kswiatk]

Thanks for all that info, that was my assumption. It would be tough to put any more money or time into this GTI.. so I may leave it as is unless a good deal comes up on an AM prop.
Just wanted to have all my bases covered.

 

[etemplet]

Yes, I sold two SeaDoos, a 96 GTI and a 95 GTX. The guy that bought the skis said the GTX pulled way better than the GTI on the low end and they liked it better for tubs, boards and such. Personally I found the GTI was about 3 mph faster on top doing my GPS testing.

Just checking but you did replace the Neoprene seal when you did the jet pump.

 

[kswiatk]

The seal is new.

 

[etemplet]

Sounds like you got all you're gonna get lol. I don't ride my skis wide open anyway. I top them out then back off some... about 5mph at least. I'm happy riding around at 35 but I also go to the wild side. LOL I prefer handling to speed that's why I like the 2 seaters.

 

[kswiatk]

Yup thats what the gsx and sp are for! The GTI was supposed to be the 3 seat tow ski.. whoops