Standard Tuning Recommendations; Adjustments For Altitude & Temperature - Honda 2005 CRF450R Owner's Manual

Carburetor Adjustments & Tuning Tips

Standard Tuning Recommendations

For the following recommendations to be
accurate, you must use the standard settings as a
baseline. Also, don't change any of the settings
until you've determined what changes are
necessary.
Adjustment Standard settings
Pilot screw opening 1 3/4 turns out
Slow jet #42
Jet needle NJYR
Needle clip position 3rd groove
Main jet #178
Float level 0.24 in (6.0 mm)
Identification number FCR00F
Adjustments for Altitude & Temperature
All jetting recommendations are based on
standard jetting with an unmodified engine. The
following conditions can affect the fuel mixture.
Condition Mixture will be:
cold temperature lean
warm temperature rich
dry air lean
high humidity rich
high altitude rich
124
Adjustments for Competition
Adjust to:
richer
leaner
richer
leaner
leaner