whats this solas concord business, sounds good

hahah
It's an impeller. or prop or blade or whatever other name it goes by.
it's what actually moves your ski forward. The OEM prop is great for all around riding.
Many of us have had success with this particular aftermarket one, it's cheaper than OEM, and gives you the best of acceleration, and you may gain 1-2 MPH top end.
removing the impeller requires special tools, or a dealer, it's NOT hard to complete, but you must do it correctly.
This is the only 'mod' that I endorse.
IF your OEM prop is damaged beyond use, replace it with this one.
I wouldn't bother replacing it if the OEM one is fine. but if / when you suck something up and it goes, get this one.
http://www.solas.com/newweb/pwcproduct/news/default.asp
http://en.wikipedia.org/wiki/Impeller
the season is so short, I used to keep a spare Solas in my garage, but when I was on a road trip w/the skis I blew an impeller.
Now I have a spare jet pump assembled and ready to swap in to my skis on the road! (both of my skis are 951s and use the same pump / parts) (yes I planned it that way)
I can't replace a wear ring / impeller on a trailer 4 hours from home, but swapping a jet pump..? an hour max maybe... it's 4 bolts for the nozzle, steering/trim, and then 4 for the pump. so maybe 1/2 hr if I need...