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In October 2000, the world
got its first glimpse of what the YZ250F was capable of as Ernesto
Fonseca ran away with the win (and a lead of more than 10 seconds) in
the All-Japan MX Final. With the YZ250F, Yamaha proved it is more than
competitive when it won six out of eight races, the 125 East/West
Shootout in Las Vegas in May 2001 and the 125cc West Championship,
making the YZ250F the first four-stroke to ever do so.
Maybe it all started in
1997 when Doug Henry won the Las Vegas Supercross aboard his YZM400
four-stroke, the first four-stroke to not only qualify for a
Supercross Main Event but actually thump the entire field en route to
the checkered flag. Maybe it started 1998 when Yamaha Motor Corp.
introduced the production YZ400F to consumers. Maybe it started when
Doug Henry clinched the 1998 National #1 Plate aboard his YZ400F.
Maybe it started in 2000 when Yamaha upped the ante with its
YZ426F. Maybe when it started is irrelevant, but one thing is
certain: Yamaha’s four-stroke technology is the benchmark by which all
other competitors and contenders are measured. Right when the
competition was approaching the starting gate, Yamaha pulled another
holeshot by introducing the 2001 YZ250F four-stroke.
With Yamaha’s
ultra-trick, titanium, five-valve, liquid-cooled, four-stroke
powerplant, the YZ250F is capable of turning out an eye-watering
13,500 rpm’s. The DOHC 249cc powerplant features a bore and stoke of
77mm x 33.6mm with a compression ration of 12.5:1. Power is supplied
via a Keihin 37mm FCR flat-side carburetor with Throttle Position
Sensor. Harnessing the power under increased loads, the YZ250F’s
five-speed transmission has superb gear-shifting operation via an
involute-spline transmission. This, combined with Yamaha’s exclusive
“works-style” adjustable clutch allows the YZ250F pilot smooth yet
durable clutch action. The YZ250F features a removable aluminum
subframe, and as if last year’s YZ250F wasn’t light enough, the weight
is reduced even further for 2002 with a newly designed rear arm just
like those of its siblings the YZ125, YZ250 and
YZ426F. The new design also improves over all handling, suspension
performance and rigidity balance, making this thumper even more race
dominant. The suspension of the YZ250F also receives several
improvements for 2002. A new two-piece piston in the front fork allows
for smoother oil flow leading to better overall suspension
performance, as does a new rear shock absorber. The forks feature
anti-section dust seals, outer tubes with low friction internals and a
lightweight aluminum piston rod for smoother suspension
characteristics. The rear shock has a fully adjustable compression
damping adjuster that allows the rider to dial in his suspension to
meet the ever-changing track conditions on race day. The front forks
feature a nylon spacer and a change in the bump rubber characteristic
while the rear shock absorber’s lower mounting section features a
needle bearing, aluminum guide and new bump rubber. These features
improve the “bottoming” feeling and reduce unsprung weight in the
rear. Its power and lightweight may be the highlights, but YZ owners
will be equally impressed with the 250F’s front brake master cylinder
and disc. A Nissin front master cylinder coupled with a “floating”
250mm front disc provides excellent stopping power and increased
controllability. With an all new 245mm rear disc brake and new, rear
brake caliper, riders will feel improved braking performance. Yamaha’s
lightweight hub, aluminum spoke nipples, and Dunlop 739FAs complete
one of the most aggressive rear setups on a production machine today.
The 2002 YZ250F is available in Team Yamaha Blue/White and will arrive
at dealerships nationwide in October 2001. The manufacturer’s
suggested retail price is $5,499. |
