Honda CRF450L 2019 User Manual

Servicing Your Honda 91
Valve Clearance
7. Lift the rocker arms (12) up and remove the
shims (13).
NOTICE
Be careful not to damage the intake rocker arms.
Do not let the shims fall into the crankcase.
Do not clean the intake rocker arms using a
commercially available compound cleaner.
1. Measure the shim thickness with a micrometer
and record it.
Seventy-three different shims (1) are available
in 0.025 mm thickness intervals, from 1.200
mm (the thinnest) to 3.000 mm (the thickest).
2. Calculate the new shim thickness using the
equation below.
A = (B – C) + D
A: New shim thickness
B: Recorded valve clearance
C: Specified valve clearance
D: Old shim thickness
• Make sure of the correct shim thickness by
measuring the shim with a micrometer.
• Reface the exhaust valve seat if carbon deposits
result in a calculated dimension of over 3.000
mm.
NOTICE
Do not lap the intake valves. They are titanium and
have a thin oxide coating. Lapping will damage
this coating.
If a calculated dimension is out of specifications,
have your motorcycle inspected by your dealer.
(12) rocker arms
(13) shims
(13) (12)
(12)
(12)
(13)
(13)
Shim Selection
(1) shim
(1)
1.80 mm 1.825 mm 1.85 mm
1.875 mm

Honda CRF450L 2019 Specifications

General

Engine Type	449cc liquid-cooled single-cylinder four-stroke
Bore x Stroke	96.0mm x 62.1mm
Compression Ratio	12.0:1
Fuel System	Programmed Fuel Injection (PGM-FI), 46mm throttle body
Transmission	6-speed
Rear Brake	Single 240mm disc
Front Tire	80/100-21
Rear Tire	120/80-18
Rake (Caster Angle)	28.5°
Wheelbase	58.9 inches
Seat Height	37.1 inches
Fuel Capacity	2.0 gallons
Ignition	Full transistorized ignition
Ground Clearance	12.4 inches
Front Suspension	49mm inverted fork; 12.0 inches of travel
Rear Suspension	Pro-Link Showa single shock, adjustable spring preload, compression and rebound damping
Front Brake	Single 260mm disc
Curb Weight	289 pounds
Valve Train	Unicam four-valve
Final Drive	Chain
Trail	4.6 inches (118mm)