2009-2010 Honda CRF450R Cylinder Head / Valve Specifications

Cylinder Head & Valve Specifications For Your 2009 – 2010 Honda CRF450R Dirt Bike.

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Part

Standard (mm)Service Limit (mm)
Cylinder Compression 57 psi (392 kPa, 4.0 kgf/cm2) @ 600 RPM –
Cylinder Head Warpage0.05

Valve and Valve Guide

Valve Clearance
– IN0.16 ± 0.03 –
– EX0.28 ± 0.03 –
Valve Stem O.D.
– IN4.975 – 4.990 –
– EX4.965 – 4.980 4.96
Valve Guide I.D
– IN 5.000 – 5.0125.052
– EX 5.000 – 5.0125.052
Stem To Guide Clearance
– IN0.010 – 0.037 –
– EX0.020 – 0.047 –
Valve Guide Projection Above Cylinder Head
– IN14.8 – 15.0 –
– EX17.8 – 18.0 –
Valve Seat Width
– IN1.1 – 1.32.0
– EX1.3 – 1.52.0

Valve Spring Free Length

– IN40.7240.6
– EX42.3042.1
Rocker Arm
– Rocker Arm I.D.12.000 – 12.01812.025
 – Rocker Arm Shaft O.D.11.977 – 11.98511.97
– Rocker Arm-to-Shaft Clearance0.015 – 0.0410.055
Camshaft
Cam Lobe Height
– IN37.540 – 37.78037.52
– EX28.598 – 28.83828.58
Valve Lifter O.D.25.978 – 25.99325.97
Valve Lifter Bore I.D.26.010 – 26.02662.04

 

Keep Your ’09-’10 CRF450r Running Right!

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