Just picked up a 2014 Yz 450 this morning. I caught the Yamaha bug on a demo day out at Pala and I really loved the motor. Coming from a fuel injected Rmz-450 Im just breaking the bike in and getting used to the different handling characteristics. Next month it will be the one year annivesary of me getting on a dirt bike for the first time, so Im pretty new to the sport. Only real coaching was 2 weeks with Rick Johnson, learning the basics and such.
Ive never ridden any of the the previous Yamaha's so I cannot compare it to earlier model years.
Power: I do know that the YZ has more power (even with wider gearing) than my Suzuki that has a full exhaust and filter. The pull is tremendous everywhere in the RPM band and the engine starts easier and quicker than my RMZ. Out of all the 2014 models this one felt the most powerful to me. Perhaps it has too much? When exiting turns on the gas the bike will either hook up and pull a 10" wheelie down the straight, or it wants to spin the rear tire. Almost like a 250 two stroke spins when it hits. The throttle is very light in its twist, good thing to keep in mind as a little turn goes a long way on this throttle.
Handling: I made zero adjustments to the suspensions and noticed how much lighter the front end felt compared the the Suzuki. I definitely have more stamina on this bike and I believe the lightness of the front end is mostly responsible for my increased energy conservation. With the new flush mount gas cap you can really position yourself high up on the tank ( I believe there is a reason for this). I need more practice sliding further up the tank to get the front wheel to hook. A few times I felt the front wheel "slip out" on me. Ive read that changing the front tire fixes this issue. Then again Ive also seen a review stating something to the effect that the bike would rather be steered more so, with the rear end, which seems to be the vibe I was getting. Overall I believe it handles very well, I simply need to get used to riding slightly different, as Ive noticed the RMZ allows one to be a little lazy and still turn in tighter on people. The YZ jumps very well, is extremely light in mid air and very predictable. Its overall balance makes very easy to jump and "place" the bike on landing.
Braking: With an good oversized rotor on my last bike its not really a good comparison, but the YZ breaks well. My only issue is that the YZ 450 seems to want to "buck and pop" when trail braking. The Suzuki didn't seem to mind being forced to decelerate hard with the rear brake and the clutch partially or totally engaged, where as the YZ fights you on this.
Fit /Finish: The new YZ is a gorgeous machine in my opinion, with much more mechanical detail put into the case and piping than some other brands I considered. Everything appears to have been done to engineer the bike, to be as competitive as possible. One thing I noticed is from where you sit on the YZ, is it feels as though the foot pegs sit further back on the bike (slightly), his doesn't appear to be a problem, simply something I need to get used to.
Overall I'm very happy with the bike, just wish somebody would hurry up and come out with plastics already so I can slap the blue ones on with the black rims. Lastly, I searched the inter webs high and low looking for a good review from a non pro rider and they were hard to come by with the bike being so new. Perhaps this will allow somebody else to make an informed decision on a new bike.