Honda CRF450R 2006, Owner'S Manual

Page: 133 / 172

Carburetor Adjustments & Tuning Tips
Adjustments for Competition
129
7. Change the main jet (4) and slow jet (5) as
required.
(4) main jet (5) slow jet
8. Reinstall the float bowl plug.
If you’ve determined that the jet needle or clip
position of jet needle must be changed, you must
remove the carburetor top.
9. Rotate the carburetor and align the lug (6) on
the carburetor with the slot (7) on the
insulator.
(8) carburetor top bolts
(9) carburetor top
13. Remove the jet needle holder (10) and jet
needle (11) from the throttle valve (12).
14. Change the clip position of jet needle or jet
needle as required.
15. Reinstall the jet needle, jet needle holder,
carburetor top and carburetor top bolts.
16. Install the fuel tank (page 31).
(10) jet needle holder (12) throttle valve
(11) jet needle
17. 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).
18. Repeat steps 4 – 16 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.
(4)
(5)
(7)
(6)
(9)
(8)
(10)
(11)
(12)
(6) lug (7) slot
10. Tighten the connecting and insulator band
screws.
11. Remove the fuel tank (page 30).
12. Remove the carburetor top bolts (8) and
carburetor top (9).
If you’ve determind that the jet needle or clip
position of jet needle must be changed, you
must remove the carburetor top.