The 1999 YZ 400F?
Let's look toward next year. We know this is early, if not totally
premature, but what the heck!
Now that Yamaha has the first YZ-400F out of the bag, what could be done that would make the bike better?
Actually, despite some of our collective complaints, all the Off-Road.com Dirt Bike staff liked the bike in some fashion. The power, appearance, and components of the bike are top notch, without a doubt. However, we question, to some degree, the use of the YZ 250 frame for the YZ 400F. Yes, we've seen Honda XR 200 engines stuffed into CR 125 frames with success; however, that hybrid design is generally suited for non-competitive purposes.
Watch Doug Henry, the factory YZ-400F racer on TV some time, and note how much he works the long way around on the majority of the turns.
While you're at it, you'll also see that Henry largely limits his cornering styles to two: (1) railing it around a berm under power, or (2) coming to a near stop, doing a little pivot on the tight inside line, and getting back on the power when the bike is vertical. Henry has had the bike spit him off numerous times this year, some of them happening while he was leading supercross main events.
We're not saying that the YZ-400F is a bad handler, its just that it requires total concentration and attention when you're riding the bike hard. One little lapse, and you can find your self down, and not know why.
Oddly enough, during our test day, we also had a chance to ride the prototype enduro WR version of the 400 (look for a write up next month!), and numerous riders said that it was actually an easier bike to ride, in spite of being substantially heavier. Since the WR has lights, the additional mass of the lighting coil (and the smoother power) makes it more predictable.
We suspect that the YZ-400F would benefit from a bit more flywheel mass and a change in the electronic ignition to allow the engine compression to become a factor in cornering again.
In straight line terrain over rough bumps, the 400 is right on and feels correct. Long sweeping turns are no problem. However, the YZ-400 really shines on bumpy downhills!
Here, the weight transfer to the front is taken care of by gravity and the bike is a pure joy on nasty slopes.
THE BOTTOM LINE!
For some reason, I'm turned off by all the electronic trickery involved with the carb and the ignition being inter-connected. Yes, I know it's bloody efficient and magical, but it also complicates things far beyond the ability of the average to comprehend, let alone work on.
Would I like to have a YZ-400F? Yes, of course. But if I did buy one (which I'm thinking about), I would remove the space-age digital-whiz-bang carb and replaced it with a good old round slide Mikuni. Then I'd remove the ignition and find something to provide a basic spark, perhaps adapting something from a TT-500, or install one of those neat Boyer units used to replace British death-trap electrical systems.
When I got done making these changes, the YZ-400F might not be as fast, or sophisticated as before, but I'd bet it would sure be more user-friendly to ride and work on."
All the same, the the 1998 Yamaha YZ 400F is already a great bike. If the handling can be adjusted so it's as predicatble as a YZ 250, or Honda XR 400, there's no doubt in our mind that not only will the Yamaha YZ 400F be the Bike of the Year, but the Bike of the Decade.