Yamaha Debuts All-New Four-Stroke YZM400F

MO Staff
by MO Staff

Yamaha released information today on a ambitious new project that will see the company go head-to-head against two-stroke motocross machinery in 1997 using a revolutionary new ultra-lightweight 400cc four-stroke MX racer.

Yamaha apparently decided to develop their innovative four-stroke off-road technology in an effort to stay ahead of growing environmental concerns over two-strokes and pending legislation that may ban the use of two-stroke motorcycles on public lands in the near future.

The company plans to field YZM400's in a full factory effort in this year's AMA 250cc Outdoor National Series, as well as entering machines in select world championship motocross grands prix in Europe.

Veteran MX racer Doug Henry has been contracted to ride the bikes in the AMA series for 1997.

According to Yamaha Motor Corp. USA Public Relations Manager Scott Heath, there are currently only two prototypes of the YZM400 in existence. "Both machines are in Japan right now undergoing further development," said Heath. "Additional machines are being produced, and we plan on having two factory works bikes for our 1997 AMA program."

Bristling with several advanced technological features, many of which have patents pending, the new machine "will meet the minimum weight requirements for the 250 class," according to Heath. Although details are sketchy at this point, it is known that the compact, lightweight 397cc single-cylinder four-stroke engine features a DOHC 5-valve cylinder head, liquid-cooling, a four-speed transmission, and will produce "over 50 hp," according to factory claims. Chassis and suspension are based on modified YZ250 components.

Four-time Dakar Rally winner Stephane Peterhansel of France, on a Yamaha, won his fourth consecutive stage.

Heath told Motorcycle Online that the YZM400F is strictly an R&D effort and no production is planned at this time.

Laporte Crashes Out of Dakar Rally American Danny Laporte dislocated his shoulder yesterday in a fall at the 508 km mark of the grueling 658-km (410-mile) fourth stage in the Dakar-Agades-Dakar Rally. Laporte had been one of the leading contenders up to that point, but the getoff effectively ended the former MX world champion's challenge in this year's event.

Four-time Dakar Rally winner Stephane Peterhansel of France, on a Yamaha, won his fourth consecutive stage. He is now more than one hour ahead of second-placed Spaniard Jordi Arcarons, while two other leading contenders in the motorcycle category also fell out of the running. Frenchmen Richard Sainct, who had a bad crash during the second stage on Sunday, fell again early on yesterday and decided to quit, nursing a hand injury. Compatriot Thierry Magnaldi, who began the stage in second place behind Peterhansel, had mechanical trouble and pulled out after 34 kms.

The fourth stage, from Nara to Timbuktoo, was interrupted between two control posts in the middle of the day when crowds of spectators spilled on to the dusty course. The race was held up for about four hours and the stage converted into two timed sections in the style of world championship rallying, with one total time given at the end of the day.

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