Sunday, April 13 was a great day for Kawasaki. The first round of the All-Japan Motocross Championship, held at the Meihan Sports Land circuit (in Nara Prefecture), marked the debut of Kawasaki's new 4-stroke motocross racer.

The technically demanding course has a range of low-speed and high-speed corners, and tricky jump combinations. The sandy base means that many areas can be traversed at full throttle - lap times are relatively quick: around 1m40s. The soft base also means that over the course of the race ruts and gaps get formed, making rider stamina and machine power essential.

Kawasaki Racing Team's Tetsuya Mizoguchi was joined by test rider Shinichi Inoue on the new 250cc 4-stroke.  In Saturday's qualifying, Mizoguchi finished his first lap in third, and calmly moved up in position until he was in the lead. He won his heat with a commanding 6-second lead.

In his own heat, Inoue maintained a steady fourth position to easily qualify for Sunday's main event.  Compared to Saturday's drizzly weather, Sunday's races were held in bright sunshine and early summer-like temperatures.

In the first moto, Mizoguchi edged Inoue for the holeshot, and despite being passed by Yamaha rider Idehara in the fifth lap, Mizoguchi kept up the pressure until an error by his rival allowed him to regain the lead. Back in front again, Mizoguchi never looked back, taking the chequered flag and giving the KX250F-SR its first victory. Inoue rode a hard-fought race to place seventh.

In the second moto, a first-lap crash by Idehara put Mizoguchi in the lead, followed by Inoue and Team Green rider Tomonori Nakamura on a 2-stroke KX125SR, giving Kawasaki the top three positions at the end of the first lap. Despite the hard-fought battle for 2nd place, Mizoguchi kept his cool, carefully selecting the best lines, and in the 4th lap set the fastest lap of the moto. Even though Suzuki rider Kitai managed to move up to 2nd place, Mizoguchi already had too great a lead, and using the ample power and torque of the KX250F-SR cruised to his second victory of the day and the first perfect win of the season. Nakamura and Inoue finished third and fifth, respectively.

Tetsuya Mizoguchi - "This is my first perfect win and I'm really happy we were able to show the potential of the new machine. But during the race, I started to suffer from arm pump, so personally I think I only performed at 80%.

"The new machine has really big torque, and the power is so easy to use - that really helped me. You have a lot of freedom in the corners so even when the course gets rough, I was able to try a bunch of different lines.

"So far I've been able to run at the head of the pack. I'd like to keep this rhythm for the rest of the season. Of course, I'll be aiming to finish on top at the next round too. At this race we've been able to appeal the new machine to our fans in Kansai. At the next race we'll show the Kanto fans what the new machine can do. 

Shinichi Inoue - "I was able to get good starts in both motos, which shows how good the new 4-stroke is off the line. Compared to a 2-stroke, the new machine has a number of good points. I was able to learn a few things during the race that hadn't come out during testing.

"As a test rider, being able to participate in some of the races is very helpful to improving the potential of the production machine. The next race is in Kanto, my home turf, so I'll definitely be looking to finish on the podium."

1. Mizoguchi - KX250F
2. Idehara - YZ125M
3. Serizawa - CRF250R
4. Nakamura - KX125
5. Kitai - RM125

1. Mizoguchi - KX250F
2. Kitai - RM125
3. Nakamura - KX125
4. Serizawa - CRF250R
5. Inoue - KX250F

• NB:  This new 250cc 4-stroke machine is the result of a joint collaboration between Kawasaki and Suzuki.  We understand that production is slated to begin in July and that the machine will be produced at Kawasaki Heavy Industries.  Early indications suggest Kawasaki have headed up the project and took the lead role in chassis development while the engine was engineered by Suzuki.  Local deliveries of the new machines are hoped to be available around September/October.