WAY too much.
has it lost power recently?
Get a flashlight and in the back of the jet pump (nozzle thing that steers) look up in there and inspect the stator, impeller and wear ring.
Turn off the light and look around it, how big of a gap between the blades and the wear ring is there? (light coming through)
then get UNDER the ski and remove the intake grate (2 bolts front, usually 1-2 rear, 10mm) and look all over it
this post shows you what your looking at
http://www.seadooforum.com/showthre...er-Pic-attached-for-diagnosis.-97-Sea-Doo-GSi
the impeller (blades) should be fairly 'clean' and smooth looking. look for chunks missing, bends, etc.
then check the wear ring (plastic ring around these blades)... if it's missing / ripped / torn etc. replace it.
Dealer will charge you tons for this, you can reduce the cost if you remove the jet pump from the ski for them (4 nuts, 4 bolts and 1 8mm steering bolt
Anyway, if your still not sure post a pic of the best you can of the insides of it.
From your post it sounds like you may be on your 1997 original impeller and wear ring.
I run a Solas Concord in my XP and I LOVE IT. I love it so much I'm going to put one in my '98 GTX.
Here's a video on how to remove your nozzle for more detailed look
http://www.youtube.com/watch?v=hjil9OdfsL8
it's not hard, just need a few tools and replacement parts. apparently this guy can do it w/out ever putting his smoke down.