Honda 2004 CRF250X Service Manual

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HIGH ALTITUDE ADJUSTMENT
(California type only)
At high altitude, the st an dard ca r bureto r air-fuel
mixture will be too rich. Performance will decrease,
and fuel consumption will increase. A very rich mix-
ture will also foul the spark plug and cause hard
starting. Oper
ation at an altitude that differs from
that at which this engine was certifie d, for extended
periods of time, may increase emissions.
High altitude performan ce can be improved by spe-
cific modifications to the ca rburetor. If your cus-
tomer always operates the motorcycle at altitudes
above 6,500 feet (2,000 meters), you should perform
this carburetor modif ication.
Even with carbur etor modification, engine horse-
power will decrease about 3.5% for each 1,OOO-foot
(300-meter) increase in altitude. The effect of al ti-
tude on horsepower will be greater than this if no
car buretor modification is made.
This engine,
when operated at high altitude with the
carburetor modifications for high altitude use, will
meet each emission standard throughout i ts useful
life.
Remove
the carburetor (page 5- 1 1).
Remove the float chamber.
Replace the
standard main jet with the high altitude
type.
HIGH ALTITUDE MAIN JET:
'04 - '06: " 128
After ' 06 : " 130
Check
that the O-ring on the float chambe r is in
good condition, replace it if necessary.
Install the float chamber.
Remove the jet needle (page 5-13).
Change the jet needle clip to high altitude clip posi-
tion.
HIGH ALTITUDE CLIP POS ITION: 1st position from
the top
Install the jet needle (page 5-23).
Install the carburetor (page 5-24).
FUEL SYSTEM
NEED LE C LI P
JE T NEE DL E
5-29

Honda 2004 CRF250X Specifications

General

Engine Type	249cc liquid-cooled single-cylinder four-stroke
Bore x Stroke	78.0mm x 52.2mm
Compression Ratio	12.5:1
Induction	Keihin 37mm flat-slide carburetor
Transmission	5-speed
Final Drive	O-ring-sealed chain
Front Suspension	47mm inverted Showa cartridge fork with 16-position rebound and 16-position compression damping adjustability; 12.4 inches travel
Rear Suspension	Pro-Link Showa single shock with spring preload, 17-position rebound damping adjustability, and compression damping adjustment separated into low-speed (13 positions) and high-speed (3.5 turns); 12.4 inches travel
Front Brake	Single 240mm disc with twin-piston caliper
Rear Brake	Single 240mm disc
Front Tire	80/100-21
Rear Tire	100/100-18
Rake (Caster Angle)	27.5°
Trail	113mm (4.4 inches)
Wheelbase	58.3 inches
Seat Height	37.7 inches
Ground Clearance	13.4 inches
Ignition	CD with electronic advance