FIRST TEST: 2009 Kawasaki KX450F

It’s hard to believe, but after winning every single National moto in 2008, the Kawasaki KX450F was obsolete. At least that seems to be the case now that we’ve ridden the 2009 version, which marks the bikes biggest change since it was released in 2006. Never mind the ’08 model’s success in pro racing, never mind the economy, never mind the credits and the debits, Kawasaki was enjoying its run in the spotlight and could not, would not let the KX450 fall behind. So the ’09 model is here and it’s the latest recruit into the world of fuel injection.

Unlike Honda and Suzuki which redesigned both their motors from scratch to accommodate EFI, the Kawasaki motor only got moderate reworking. It was already the newest of those motors and it now seems that Kawasaki had fuel injection in mind from the start. The bike has a massive new generator that supplies power from the initial movement of the kickstarter in sequence to the ECU, then to the fuel pump then to the injectors. Kawasaki claims one-kick starting. The bike also got a revised decompression system to help with starting. Additionally the head is more compact and there is a new (higher compression ) piston, new valve material and a beefier rod.

There are a lot of other changes that have nothing to do with fuel injection. The frame is new with more compact rails and a higher swingarm pivot. The swingarm with its ‘D’ shaped arms is supposed to be almost a half-pound lighter and the sub-frame is tougher. The KYB shock body is new as is the valving and there’s 1 mm less offset in the fork triple clamps. Kawasaki still has the ‘Diamond-Like’ fork coating, which aside from the corny name is a good idea to increase seal life and decrease friction. When you consider the other details like the wider pegs, the new skid plate, the narrower chain guard and the wrap-around fork guards, it’s apparent that Kawasaki made a major investment in the KX.

Kawasaki let us ride the new bike for the first time at Muddy Creek, Tennessee. First things first: the bike is responsive. Crazy responsive. When you crack the throttle there’s no hesitation, no cough, no sputter, just instant power. Remember the KX already was so powerful that Kawasaki detuned it slightly last year. Now it has as much power down low as ever, although it probably tapers off a little earlier. As far as fuel mixture goes, the bike has no glitches. It really does start with one kick most of the time and throughout the day it never stalled, except for the time we deliberately brought it down to an idle and stomped on the brake.
We spent more time analyzing the suspension. Muddy Creek was anything but muddy. It was tacky clay with good traction, and that seemed to confuse the KYB shock slightly. In the end we got it to work best by slowing down the rebound damping. Then the bike handled predictably. It’s kind of a big motorcycle, and even though the frame is narrower this year, it was hard to notice without back-to-back comparison.

Since we got to ride the 2009 Honda last week in Texas, some comparisons are irresistible, if perhaps unscientific. The Honda was ridden on a completely different track, but still we can offer some general impressions. The Kawasaki started easier and stalled less often. The Kawasaki also seemed to have more bottom-end power and faster throttle response. The Honda revved higher and had a smoother power delivery. We’ll also say that the Honda felt lighter.
Well have more hard-core test information in the December issue of Dirt Bike.