Good to hear someone out there bought an excellent quad. I bought mine new about four months ago and so far I've installed a DG chrome header and spark arrestor. It made a huge difference in performance if you don't mind a little more noise coming from the bike. I've heard installing a K & N power jet kit will boost performance as well although my mechanic recommends against it. He says K & Ns are good on cars, but on off-road vehicles they tend to let too much debree by into the carb. He told me if I were to install one on my quad, I should probably go ahead and get the Outerwear for it. If you install a pipe, you will definitely have to tweak on the carb, if not rejet it. I had to lower my needle a notch because the pipe made it run way too lean. As far as tires go, the stockers suck. I am waiting until I can find a good deal on Maxxis Raz'rs or Holeshot XTPs. Rubber makes a great deal of difference, not necessarily on take-off but more on the handling end of things... I'd be interested in finding out what changes you made to your quad. As far as warranty goes, it didn't really matter to me as long as the thing didn't fall aprart the first week I had it. Yamahas tend to be very strong, reliable, well-built machines. Hope you enjoy yours.....
warrior2000
2000 Yamaha Warrior
1997 Suzuki RM250