Honda CRF250R Owner's Manual page 132

12.Change the main jet (4) and slow jet (5) as
required.
(4)
(5)
(4) main jet (5) slow jet
13. Reinstall the float bowl plug.
14.If you've determined that the jet needle or clip
position of jet needle must be changed, you
must remove the carburetor top.
15.Remove the fuel tank (page 30).
16.Rotate the carburetor to the left and remove the
carburetor top bolts (6) and carburetor top (7).
(7)
(6) carburetor top bolts
(7) carburetor top
17.Remove the jet needle/holder assembly (8).
(8) jet needle/holder assembly
(9)
(9) clip
(10) jet needle holder
(11) jet needle
(6)
18.Remove the clip (9) and jet needle (11) from
the jet needle holder (10).
Change the jet needle clip position or jet
needle as required.
Carburetor Adjustments & Tuning Tips
(8)
(11)
(10)
19.Reinstall the jet needle/holder assembly,
carburetor top and carburetor top bolts.
20.Rotate the carburetor and align the lug (12) on
the carburetor with the slot (13) on the
insulator.
(12) lug (13) slot
21.Tighten the connecting and insulator band
screws.
22.Install the fuel tank (page 31).
23.Start the engine.
If the engine idle speed is too high or too low
or engine is not idling, adjust the engine idle
speed (page 48).
24.Repeat steps 4 – 23 until the engine gives
maximum power with the correct spark plug
reading. It is always better to jet a little rich
than a little lean. It is advisable to record the
settings, course conditions, lap times, and
climatic and barometric conditions for future
reference.
Adjustments for Competition
(12)
(13)
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