Honda CRF450RX 2020 User Manual

Throttle
70 Servicing Your Honda
Throttle
Refer to Important Safety Precautions on page 23.
Inspection
Check freeplay (1).
Freeplay: 1/16 – 1/4 in (2 – 6 mm)
If necessary, adjust to the specified range.
Upper Adjustment
Minor adjustments are generally made with the
upper adjuster.
1. Loosen the lock nut (1).
2. Turn the adjuster (2).
Turning the adjuster in direction (–) will
decrease freeplay and turning it in direction (+)
will increase freeplay.
3. Tighten the lock nut securely.
4. After adjustment, check for smooth rotation of
the throttle grip from fully closed to fully open
in all steering positions.
If the adjuster is threaded out near its limit or
the correct freeplay cannot be reached, turn the
adjuster all the way in and back out one turn.
Tighten the lock nut securely.
Make the adjustment with the lower adjuster.
Lower Adjustment
The lower adjuster is used for major freeplay
adjustment, such as after replacing the throttle
cables or removing the throttle body. It is also used
if you cannot get the proper adjustment with the
upper adjuster.
1. Loosen the lock nut (1).
2. Turn the adjuster (2) in direction (–) to
decrease freeplay, and in direction (+) to
increase freeplay.
3. Tighten the lock nut to the specified torque:
3.0 lbf·ft (4.0 N·m, 0.4 kgf·m)
4. Operate the throttle grip to ensure that it
functions smoothly and returns completely.
If you can’t get the freeplay within the specified
range, contact your dealer.
Throttle Freeplay
(1) freeplay
(1)
(1) lock nut (+) increase freeplay
(2) adjuster (–) decrease freeplay
(2)
(1)
(+)
(–)
(1) lock nut (+) increase freeplay
(2) adjuster (–) decrease freeplay
(1)
(2)
(–)
(+)

Honda CRF450RX 2020 Specifications

General

Engine Type	449cc liquid-cooled single-cylinder four-stroke
Bore x Stroke	96.0mm x 62.1mm
Compression Ratio	13.5:1
Induction	Programmed Fuel Injection (PGM-FI), 46mm throttle body
Ignition	Full transistorized ignition
Transmission	5-speed
Final Drive	Chain
Front Brake	Single 260mm disc with twin-piston caliper
Rear Brake	Single 240mm disc
Front Tire	80/100-21
Rear Tire	120/80-18
Wheelbase	58.3 inches
Seat Height	37.8 inches
Ground Clearance	12.9 inches
Starter	Electric
Trail	4.6 inches
Front Suspension	49mm inverted fork with rebound and compression damping adjustability; 12.0 inches travel
Rear Suspension	12.4 inches of travel
Valve Train	Unicam, four-valve