Honda CRF450R 2011 User Manual

84 Servicing Your Honda
Piston/Piston Rings/Piston Pin
1. Place clean shop towels in the crankcase to
keep the piston pin clips, or other parts, from
falling into the crankcase.
2. Remove the piston pin clips (1) using a pair of
needle-nose pliers.
3. Press the piston pin (2) out of the piston (3),
and remove the piston.
Under racing conditions, the piston and rings
should be replaced every 6 races or about every
15.0 hours of running. Replace the piston pin every
12 races or about every 30.0 hours of running.
Spread each piston ring (1) and remove by lifting it
up at a point just opposite the gap.
NOTICE
Do not damage the piston ring by spreading the
ends too far.
We recommend you consult an official Honda
Shop Manual or your Honda dealer for correct
Service Limit measurements.
Piston Removal
(1) piston pin clips (3) piston
(2) piston pin
(2)
(3)
(1)
Piston Ring Removal
(1) piston ring
(1)
Piston/Piston Pin/Piston Ring Inspection
CRF450R.book Page 84 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