Hi,
I have a Yamaha Gp1300R (165BHP on a 300kg ski!!) and had a GP1200R before that so have been at it quite a while. I started up a forum site (not of the quality of this one I must add) some time ago and there are message boards on there.... you might wanna look:
www.PWCIreland.com and click message boards. Go on and ask the lads for some advise. My advise.... Uel in
www.JetProducts.net up North. Super guy and well worth the trip. Go Yamaha, they last longest!
Adrian