YZ 250F
The first
YZ 250F shocked a whole lot of people by dominating the 125cc West
Regional Supercross series, with wins in five of eight rounds. For
the new year, some changes were in line for the high-revving 250
four-stroke For the new year, some changes were in line for the
high-revving 250 four-stroke racer.
The titanium-valved, liquid-cooled, quarter-liter rocket received
some fine-tuning in the carburetor for crisper throttle response,
and got some remapped ignition work for greater firing precision.
More: reworking the suspension settings and adding an all-new,
lighter-weight swingarm for smoother, more responsive handling
performance. Beefing up the brakes with an all-new 245mm rear disc.
And moving the handlebar mounts ever so slightly forward to improve
ergonomic comfort and create a more aggressive riding position.
NEW FOR 2002:
-
Revamped carburetor settings deliver crisper,
more linear throttle response for optimal engine
output.
- Remapped digital CD ignition system delivers more precise spark
and optimal timing for faster, stronger response during hard
acceleration, and less kickback during starting.
- All-new hydroformed swingarm is lighter and stronger for
reduced weight, greater rigidity and more compliant rear suspension
action, while an anodized finish gives it a trick, factory
team-style look.
- Rear shock refinements include improved actuation, a new
linking ratio and enhanced damping force.
- Revamped front fork settings deliver improved damping force
with less bottoming for a smoother, more compliant overall
stroke.
- Lightweight front wheel hub reduces unsprung weight and
increases durability.
- Larger rear brake disc means greater stopping power.
- Reworked handlebar mounts are increased in size to help
accommodate a wider range of riders.
Engine:
-
Liquid-cooled, 249cc, 5-valve, DOHC, 4-stroke
is the world's most powerful, quarter-liter 4-stroke motocrosser
with a stratospherically high, 13,500-rpm redline.
-
Titanium valves and load-reduced springs
decrease weight by more than 40% and reduce reciprocating mass for
faster-revving, harder-hitting power delivery across the rev
range.
-
Trick, works-style clutch lever features
race-spec barrel adjuster for on-the-fly
adjustability.
-
Slick-shifting, 5-speed transmission with
heavy-duty, multi-plate clutch features an involute spline setup,
ensuring smoother shifting and instant hookup under power, as well
as reduced horsepower loss.
-
37mm Keihin FCR flat-slide carburetor with
throttle position sensor (TPS) ensures ultra-precise fuel/air
mixing and lightning-quick throttle response.
-
Digital CD ignition system delivers more
precise spark and monitors engine speed to ensure optimal timing
for faster, stronger response during hard
acceleration.
-
Large-capacity radiator provides outstanding
cooling efficiency.
-
Lightweight exhaust system with specially
shaped header angle maximizes engine power and allows hassle-free
replacement of oil filter.
-
Aluminum exhaust silencer looks trick and
reduces weight.
-
Primary kickstarting with integrated hot-start
button ensures easy restarts in any gear.
-
Dry sump lubrication system uses frame as oil
tank, helping to create a more compact engine and chassis for
superb handling performance.
-
Magnesium cylinder head cover helps shave
weight.
Chassis/Suspension:
-
Ultra-rigid, high-tension steel, YZ 125-style
twin-spar frame is super-lightweight and strong for minimal
flex.
-
Lightweight 46mm inverted Kayaba cartridge
fork features 11.8" of travel with compression and rebound
adjustability.
-
Low-friction outer tubes and aluminum piston
rods ensure smoother, more compliant fork stroke for superior
handling and lighter steering.
-
Removable aluminum rear subframe reduces
weight and allows easy maintenance.
-
Rear suspension system features fully
adjustable Kayaba shock with 12.4" of travel and separate adjusters
for high- and bow-speed compression damping.
-
YZ-426F-spec brake system features all-new
250mm fully floating front disc and 245mm rear disc
brakes.
-
Lightweight 21" front and 19" rear rims
provide exceptional durability and help reduce unsprung weight for
optimal suspension performance.
-
Premium Dunlop 739 knobbies offer
competition-spec traction and excellent wear.
-
Specially designed steering crown, seat, fuel
tank, handlebar, footpegs and radiator shrouds create ergonomically
balanced riding position that permits easy rider movement and
greater weight transfer flexibility during aggressive
riding.
-
Team Yamaha-inspired two-tone (black/blue)
seat.
-
Wide, cleated, folding cast alloy footpegs
provide excellent comfort, grip and ground
clearance.
-
Cleated rear brake lever and folding shift
lever tip offer superb grip and excellent
durability.
-
Repackable exhaust silencer.
-
Durable, comfortable handlebar
grips.
-
Stainless steel clutch cable for longer
life.
Specifications:
MSRP |
$5,499* Available from
October 2001 |
Engine |
Type |
249cc, liquid-cooled, 5-valve, DOHC, 4-stroke
w/titanium valves |
Bore x stroke / mm |
77 x 53.6mm |
Final Drive |
#520 chain |
Compression Ratio |
12.5:1 |
Carburetion |
37mm Keihin FCR flat-slide w/throttle position
sensor |
Ignition |
Digital CDI |
Transmission |
5-speed w/multi-plate wet clutch |
Suspension |
Front |
46mm Kayaba inverted telescopic fork
w/adjustable compression and rebound damping; |
Travel |
11.8 |
Rear |
Kayaba single shock w/adjustable preload, compression and
rebound damping & separate hi/b-speed compression
adjuster; |
Travel |
12.4 |
Dimensions/Other |
Tire - Front |
80/100-21 |
Tire - Rear |
110/90-19 |
Length |
84.9" |
Width |
32.6" |
Dry Weight |
n/a |
Height |
51.3" |
Fuel Capacity |
2.1 gallons |
Wheelbase |
58.1" |
Seat Height |
39.3" |
Ground Clearance |
15.0" |
Color |
Team Yamaha Blue/White |
|