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New Crosser 2004

Tactical variant

Two-stroke or four-stroke? Certainly also a question of taste. But the trend is clear: four-stroke crossers are en vogue, and a whole wave of new models is rolling in 2004.

When Jacky Martens defeated the half-liter two-stroke engine on a 630 Husky in 1993, no one could have imagined that two-stroke engines would also
are conquerable in the smaller displacement classes. How should a four-stroke beat the aggressiveness, liveliness and dynamism of a two-stroke 250? Quite simply, primarily with more displacement, as in the large class. This was only granted to the four-stroke engines in the two smaller classes in 2003: 250 four-stroke engines are now allowed to compete in the eight-liter class and 450 in the quarter-liter category. Secondly, however, a technical revolution was necessary. Yamaha introduced this in 1998 with the legendary YZ 400 F, the first high-revving four-stroke engine in a compact two-stroke chassis.
In year one of the new cubic capacity-
Regulations already drive the four-stroke engines strongly around the world championships. Mickael Pichon has to fight off a whole pack of four-stroke 450s on his two-stroke Suzi. And in the
small class the barking Yamahas heat the screeching 125 cc. The general attack is still ahead, however, in 2004 a true four-stroke model flood comes from Japan. After the economic drought, Husqvarna finally wants to deliver new models, and KTM
is currently working on the new quarter-liter dohc engine. In 2004, only a small series should be available for works pilots and a few top drivers, the series model will not follow until 2005.
Surely that does not mean the end of the two-stroke, especially all two-stroke-
M.models to start the new year with lots of detail improvements. They remain victorious, but for how long?

Kawasaki

The oven-stroke engine developed by Kawasaki together with Suzuki made its debut under the name KX 250 F. In the first race in the Japanese championship, the Kawa landed an instant victory. Technically, the small four-valve engine is similar to the Yamaha engine, bore and stroke are exactly the same at 77 and 53.6 mm. But it looks more compact, the cylinder is only a few centimeters high. The semi-dry sump lubrication blinds the oil in the crankcase while the crankshaft rotates in a sealed space. The flywheel mass can be varied with optionally available, different rotors. Kawasaki states 43 hp at 92.5 kilograms for the new four-stroke engine. All Kawa-Crossers have a new lever system for the rear suspension.

Honda

At the end of last year, Honda presented the first photos of a 250 sister of the successful 450, now the CRF 250 R appears as a 2004 model. It is astonishing that Honda can achieve the required speeds of over 13000 rpm with the Unicam engine, in which a relatively heavy rocker arm operates the exhaust valves. The crankshaft drive and clutch / gearbox have separate oil circuits with small pumps and small amounts of oil. The engine hangs in a fourth generation aluminum frame, while the other 2004 machines are based on the previous model. Further information: bore / stroke 78 / 52.2 mm, power 35.2 hp, dry weight 94.5 kilograms.

Suzuki

As early as 2002, Suzuki and Kawasaki announced a close cooperation, and now the new 250cc four-stroke is the first jointly developed crosser. The RM 250 Z is identical in every detail to the Kawa, only the yellow plastic distinguishes it from the green counterpart. The machines roll off the assembly line at Kawasaki, and the chassis with the perimeter frame is typical for Kawa. The two-stroke models remain "pure"Suzuki. New to them: the lever system of the rear wheel suspension, low seat height, more flywheel mass for better traction.

Yamaha

Yamaha initiated the four-stroke trend in 1998 and has established itself excellently for years with a complete tidy of models. In 2004, all machines received thicker, yet lighter 48-inch forks with improved responsiveness. Wear-resistant titanium footpegs save a few grams of weight. The exhaust manifold of the otherwise largely unchanged 250cc five-valve four-stroke engine is now also made of titanium. The 450, feared because of its aggressive characteristics, also remains almost unchanged. A revised ignition system should optimize controllability, the criticized clutch was modified.

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