Yamaha yz450f 2007 User Manual

4 - 31
ENG
CYLINDER HEAD
INSPECTION
Cylinder head
1. Eliminate:
• Carbon deposits (from the combustion
chambers)
Use a rounded scraper.
N
OTE:
Do not use a sharp instrument to avoid damag-
ing or scratching:
• Spark plug threads
• Valve seats
2. Inspect:
• Cylinder head
Scratches/damage → Replace.
3. Measure:
• Cylinder head warpage
Out of specification → Resurface.
Cylinder head warpage:
Less than 0.05 mm (0.002 in)
Warpage measurement and re-surface-
ment steps:
• Place a straightedge and a feeler gauge
across the cylinder head.
• Use a feeler gauge to measure the
warpage.
• If the warpage is out of specification,
resurface the cylinder head.
• Place a 400 ~ 600 grit wet sandpaper on
the surface plate, and resurface the head
using a figure-eight sanding pattern.
N
OTE:
To ensure an even surface rotate the cylin-
der head several times.

Yamaha yz450f 2007 Specifications

General

Engine Type	449cc liquid-cooled DOHC 4-stroke; 5 titanium valves
Bore x Stroke	95.0mm x 63.4mm
Compression Ratio	12.5:1
Ignition	CDI
Transmission	5-speed
Final Drive	Chain
Front Tire	80/100-21
Rear Tire	120/80-19
Seat Height	39.1 in
Fuel Capacity	1.8 gal
Dry Weight	220 lb
Front Brake	Hydraulic single disc, 250mm
Rear Brake	Hydraulic single disc, 245mm
Overall Width	32.5 in
Overall Height	51.2 in