Honda 2007 CRF250R, Руководство пользователя

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Carburetor Adjustments & Tuning Tips
126
Adjustments for Competition
Carburetor Minor Adjustments
The standard carburetor settings are ideal for the
following conditions: sea level altitude, and 20°C
(68 °F) air temperature. If your conditions are
different, you may need to adjust the carburetor
settings, using the tuning information on page
124 and 125. Confirm your settings are correct
before proceeding.
Minor Adjustments
1. Adjust the carburetor setting using the tuning
information on page 124 and 125.
2. When the engine is warm enough to run
without the choke, push the choke knob down
to its off position.
3. Adjust the pilot screw (1) to obtain the best
off-idle performance.
– If the engine blubbers (rich) exiting a
corner, turn the pilot screw clockwise to
lean the mixture.
– If the engine surges (lean) exiting a corner,
turn the pilot screw counter clockwise to
richen the mixture.
The minimum to maximum range of pilot screw
adjustments is 1 3/4 to 2 1/2 turns out from the
lightly seated position. If you exceed 2 1/2 turns
out, the next larger slow jet is needed. If you are
under 1 3/4 turn out, the next smaller slow jet is
needed.
(1) pilot screw
Adjustment Procedure
1. Turn the pilot screw in until it is lightly seated
and record the number of turns. Turn the pilot
screw out the same number of turns.
2. Warm up the engine.
3. Adjust the engine idle speed (page 48).
4. Make two or three laps of a course with the
standard setting or corrected jetting (page
124). and spark plug. Note engine
acceleration and other engine conditions in
relation to throttle opening. Verify
carburetion by removing the spark plug and
reading its firing end (page 128). It may take
more than two or three laps to get a good
spark plug reading with a new spark plug.
5. Change carburetor settings or select suitable
carburetor jets, taking into consideration the
engine conditions and factors for temperature
and altitude (page 124).
(2) drain screw (3) float bowl plug
(1)
(3)
(2)
6. Adjust the pilot screw as required.
10. Loosen the connecting and insulator band
screws. Rotate the carburetor.
11. Remove the float bowl plug (3).
WARNING
Gasoline is highly flammable and
explosive. You can be burned or
seriously injured when handling fuel.
• Stop the engine and keep heat, sparks
and flame away.
• Handle fuel only outdoors.
• Wipe up spills immediately.
7. If you’ve determined that the main and slow
jets must be changed, you must rotate the
carburetor and remove the float bowl plug.
8. Turn the fuel valve OFF, and disconnect the
fuel line from the fuel valve.
9. Drain the remaining fuel in the float bowl by
loosening the drain screw (2). Then tighten
the drain screw after draining the fuel.
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