Honda CRF250R 2005, Owner'S Manual

Page: 129 / 164

Carburetor Adjustments & Tuning Tips
Adjustments for Competition
125
11.Change the main jet (3) and slow jet (4) as
required.
(3) main jet
(4) slow jet
12. Reinstall the float bowl plug.
13.If you’ve determined that the jet needle or clip
position of jet needle must be changed, you
must remove the carburetor top.
14.Remove the fuel tank (page 30).
15.Rotate the carburetor to the left and remove the
carburetor top bolts (5) and carburetor top (6).
(5) carburetor top bolts
(6) carburetor top
16.Remove the jet needle holder (7), insert the
carburetor maintenance tool (8) to the jet
needle (9) from the throttle valve (10), and
remove it.
(7) jet needle holder
(8) carburetor maintenance tool
(9) jet needle
(10) throttle valve
17.Change the clip position of jet needle or jet
needle as required.
18.Reinstall the jet needle, jet needle holder
carburetor top and carburetor top bolts.
19.Install the fuel tank (page 31).
20.Rotate the carburetor and align the lug (11) on
the carburetor with the slot (12) on the intake
tube.
(11) lug (12) slot
21.Tighten the connecting and intake tube band
screws.
22.Connect the fuel line.
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.
(3)
(4)
(3)
(4)
(5)
(6)
(7)
(8)
(10)
(9)
(11)
(12)