Honda CRF450R 2006 User Manual

Carburetor Adjustments & Tuning Tips
126 Adjustments for Competition
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
Pilot screw opening
Slow jet
Jet needle
Needle clip position
Main jet
Float level
Identification number
Standard settings
1 1/2 turns out
#42
NCYQ
4th groove
#168
0.31 in (8.0 mm)
FCR00E
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
cold temperature
warm temperature
dry air
high humidity
high altitude
Mixture will be:
lean
rich
lean
rich
rich
Adjust to:
richer
leaner
richer
leaner
leaner

Honda CRF450R 2006 Specifications

General

Engine Type	449cc liquid-cooled single-cylinder four-stroke
Bore and Stroke	96.0mm x 62.1mm
Compression Ratio	12.0:1
Induction	Keihin 40mm flat-slide carburetor with throttle position sensor (TPS)
Transmission	Close-ratio five-speed
Final Drive	#520 chain; 13T/48T
Front Brake	Single 240mm disc with twin-piston caliper
Rear Brake	Single 240mm disc
Front Tire	80/100-21
Rear Tire	110/90-19
Wheelbase	58.3 inches
Seat Height	37.6 inches
Ground Clearance	13.4 inches
Fuel Capacity	1.9 gallons
Ignition	CDI
Rear Suspension	Pro-Link Showa single shock with spring preload, 17-position rebound damping adjustability, and compression damping adjustment separated into low-speed (13 positions) and high-speed (3.5 turns); 12.4 inches travel