Pros: Plenty of power, hooks up well
Cons: Plenty of weight, poor turning, poor accelleration
One of my favorite things about the YZ426 is how easy it is to 80 mph wheelies forever. I made the decision to buy a new YZ426 based on experience riding a friend's 2000 model. I didn't like the hitches and bogs in the carburetor, but that was supposedly fixed on the 2001 model. The carb problems were indeed fixed and I was a happy camper with my new bike. For the most part. I really like the power delivery and I didn't really have any trouble getting used to it. I didn't get any faster as my riding style more closely fits a heavily modified two stroke, but I was able to keep up the pace more often than not. New springs and valves in the fork and shock made a world of difference in allowing the bike to handle the entire track instead of parts of the track. I ride supercross and arenacross almost exclusively and things tend to get a little rough with a heavy bike. However, the suspension performed quite well in stock form. The engine seemed to be a little slow on power delivery and I found myself frying the clutch at any point in the RPM range to get just that last little bit out of it. Consultation with the local GYTR dealer revealed a part list exceeding $2,200 just to bring the power up to what I wanted out of the engine. That list was for parts only, no head mods or labor. This is an awesome bike, just not for me. Get the weight down to two stroke level and put some more snap in the engine and I may reconsider. We'll have to see Yamaha's answer to the CRF450.
Now on to the details. . .
I feel that the YZ426 is a machine that isn't quite finished. Given the engineering expertise that Yamaha has shown in the past, the YZ426 could stand some improvement. Before I ever rode my 426, I took it home and disassembled every bearing on the bike. They were all severely lacking any lubrication whatsoever. I cleaned, greased, and reassembled the bike. I chose to use blue Loctite on all the plastic fasteners as excessive bolt torque will distort the plastic. On my first ride, I lost a bolt out of the right radiator shroud and most of the rest were loose. I didn't think I could forget to torque that many bolts as I have been wrenching on my own bikes for 15 years but I took it in to the Yamaha dealer anyway. They used RED Loctite on all the plastic bolts. Next ride, the left number plate fell off and my friend's 2000 YZ426 lost a couple of bolts as well. Oh, well. That's the way of Yamaha. Graphics fall off, bolts fall out, plastic falls off. Take your tool kit with you everywhere.
I would have to recommend this bike to any pro level rider with a lot of money to spare or to anyone else that wants the world's most awesome play bike. Take a look at all the mods done to the 426's the pros ride and you will agree.