Honda CR250R 2004 Owner's Manual page 51

5. CARBURETOR ADJUSTMENT
To assemble, reverse the disassembly procedures.
To install the carburetor, reverse the removal proce-
dures.
NOTE:
•
After installing the carburetor, check the air vent
tubes and overflow hose for kinking or pinching
and correct routing as necessary.
1
2
(1) AIR VENT TUBES (2) OVERFLOW HOSE
48
Pre-adjustment Checks
Before adjusting carburetor settings, check the follow-
ing:
1. air cleaner condition (page 23)
2. air leaks
3. ignition timing
4. float level
5. clogged carburetor jets
6. spark plug fouling or improper heat range
7. freshness of fuel and fuel/oil ratio
1
If the above check out, adjust the carburetor for your
specific racing conditions. Engine response and ap-
pearance of the firing end of a spark plug are highly
indicative of the engine condition.
Refer to the list on page 9 for the optional carburetor
parts.
Adjustment Procedure
1. Warm up the engine.
2. Make two or three laps of a course with the standard
or corrected jetting (see page 50) and spark plug.
Note engine acceleration and other engine condi-
tions in relation to throttle opening. Verify
carburetion by removing the spark plug and read-
ing its firing end (page 22, 51). It may take more than
two or three laps to get a good spark plug reading
with a new spark plug.
3. Change carburetor settings or select suitable car-
buretor jets, taking into consideration the engine
conditions and factors for temperature and altitude
(page 50).
4. If you've determined that the main and slow jets
must be changed, you must remove the float bowl.
•
Removing the float bowl plug will allow the fuel in
the float bowl to drain. Do not remove if engine is
hot.
•
Gasoline is extremely flammable and is explosive
under certain conditions. Perform this operation in
a well-ventilated area with the engine stopped. Do
not smoke or allow flames or sparks in the area
where gasoline is drained or stored and where the
fuel tank is refueled.
5. Turn the fuel valve OFF, and disconnect the fuel line
from the fuel valve.
6. Remove the drive sprocket cover.
7. Loosen the connecting and intake tube bands. Ro-
tate the carburetor. Remove the float bowl plug.
(1) FLOAT BOWL PLUG (2) OVERFLOW HOSE
(3) FLOAT BOWL SCREW