The 2009 All Japan National MX Championship Series got underway today at Kyushu Sports Park in Kumamoto, Japan, and several special works bikes made their debut at the Honda-owned and operated facility. Because the machines of the MFJ series are not limited by a production rule, manufacturers are allowed to field prototype, pre-production, a full-works machines.

This weekend, the standout bikes were the Kawasaki KX250F and Suzuki RM-Z250s, both of which featured electronic fuel injection. Both were reported to be pre-production 2010 units, so it appears that EFI will make its way into the Lites class for 2010.

Aside from the EFI throttle body, the Kawasaki KX250F piloted by Shin Inouye looked much like an existing '09 KX250F. As has become par for the course, the factory Kawasaki's—even though exotic enough in their own rite—remained the most subdued in appearance.

A few days ago, TransWorld Motocross already spotted the pre-production Suzuki RM-Z250 in action at Glen Helen Raceway Park, but the bike raced in Japan by Suzuki factory rider Yutaka Hoshino was much, much tricker. As they are in the United States, the factory Suzukis in Japan have the highest bling factor.

Also on hand for the third year in a row was the EFI Honda CRF250R, piloted by Yu Hirata. This machine was a pure works bike, however, and we were told that the 2010 production EFI CRF250R will look much like the 2009 CRF450R.

No special Yamaha YZ250Fs were on hand at Kyushu, mostly due to the fact that Yamaha Japan has cancelled its official factory motocross race team effort. The satellite Team YZ squad was mounted on stock-looking '09 YZ250Fs. Our inside sources at Yamaha Japan, however, indicate that there are no major engine changes in store for the 2010 Yamaha YZ250F, though the bike will receive an all-new chassis and bodywork, plus revised suspension settings.

As for the all-new Yamaha YZ450F, defending All Japan National MX Champion Akira Narita raced a privateer '09 YZ450F (under the YSP/Narita Racing Team banner) with a combination of works Yamaha parts and Rinaldi Racing parts from Italy. Though the radically all-new pre-production 2010 YZ450F—which features EFI, a forward-tilted engine and an all-new chassis and bodywork—was said to be ready for Narita to race, word in the pits was that Yamaha Motor Corp. USA demanded that the bike not be unveiled in Japan just yet. Poor sales of the '09 YZ450F mandate that the '10 model not make its competition debut until September, at the All Japan National MX series finale.

Like Yamaha, Honda Japan dropped its factory motocross race team effort, but special HRC machines were provided to the Dream Honda team, which includes 250F rider Hirata, as well as 450 pilots Yoshihide "The Best Last Name Ever" Fukudome and Kazumasa Masuda. The Dream Honda CRF450Rs boasted plenty of trick parts; most notably Fukudome's radical works Showa front forks.

The Suzuki RM-Z450s were pre-production 2010 units, with works throttle body parts and EFI components. Though it looks the same to the naked eye, the '10 RM-Z450 boasts a new chassis with much-improved geometry. The engine settings are also said to be much different for '10, gravitating towards the more aggressive side.

The factory Kawasakis featured the normal works parts—suspension, triple clamps, etc.—but nothing radically different than stock grabbed our eye. Many expect last year's IA2 champion, Hiroake Arai, to make a big splash this year as he steps up to the IA1 division in '09.

Below, you will find a 200+ photo gallery slideshow. To view the photos at your own pace, or to enlarge them to check out the detail, click the link below that says “Click here to download images.” Enjoy! – Swap-san