Honda CRF450R 2011 User Manual

Valve Clearance
72 Servicing Your Honda
Valve Clearance
Refer to Safety Precautions on page 27.
Excessive valve clearance will cause noise and
eventual engine damage. Little or no clearance will
prevent the valve from closing and cause valve
damage and power loss. Check valve clearance
when the engine is cold at the intervals specified in
the Maintenance Schedule (page 29).
The checking or adjusting of the valve clearance
should be performed while the engine is cold.
The valve clearance will change as engine
temperature rises.
Before inspection, clean the engine thoroughly to
keep dirt from entering the engine.
1. Remove the seat and hang the fuel tank to the
left of the frame (pages 37, 38).
2. Disconnect the breather tube (1) and spark
plug cap (2).
3. Remove the cylinder head cover socket bolts
(3), rubber seals (4) and cylinder head cover
(5).
1. Remove the crankshaft hole cap (1).
2. Remove the spark plug (page 71).
3. Remove the cylinder head cover (page 72).
Cylinder Head Cover Removal
(1) breather tube (2) spark plug cap
(3) cylinder head cover socket bolts
(4) cylinder head cover rubber seals
(5) cylinder head cover
(1)
(2)
(5)
(3)
(4)
Positioning At TDC On The
Compression Stroke
(1) crankshaft hole cap
(1)
CRF450R.book Page 72 Thursday, July 8, 2010 9:34 AM

Honda CRF450R 2011 Specifications

General

Engine Type	449cc liquid-cooled single-cylinder four-stroke
Bore x Stroke	96.0mm x 62.1mm
Compression Ratio	12.0:1
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	120/80-19
Trail	114mm (4.5 inches)
Induction	PGM-FI, 46mm throttle body
Front Suspension	48mm inverted with rebound and compression damping adjustability; 12.2 inches travel
Rear Suspension	Pro-Link single shock with rebound and compression damping adjustability; 12.4 inches of travel
Wheelbase	58.7 inches
Seat Height	37.6 inches
Fuel Capacity	1.5 gallons