Yamaha 2012 Grizzly 300 Service Manual page 127

CYLINDER HEAD
CHE CKING THE CYLINDER HEAD COVER
ASSY.
1. Check:
• cylinder head cover assy.
• o-rings
Cracks/damage
EBS00230
CHECKING THE CYLINDER HEAD
1. Eliminate:
• combustion chamber carbon deposits
(with a rounded scraper)
TIP
Do not use a sharp instrument to avoid damag-
ing or scratching:
• spark plug bore threads
• valve seats
2. Check:
• cylinder head
Damage/scratches
3. Measure:
• cylinder head warpage
Out of specification
der head.
Maximum cylinder head warpage
<Limit>: 0.05 mm (0.002 in)
a. Place a straightedge and a thickness gauge
across the cylinder head.
b. Measure the warpage.
c. If the limit is exceeded, resurface the cylin-
der head as follows.
d. Place a 400 ~ 600 grit wet sandpaper on
the surface plate and resurface the cylinder
head using a figure-eight sanding pattern.
TIP
To ensure an even surface, rotate the cylinder
head several times.
4-7
ENG
→
Replace.
→
Replace.
→ Resurface the cylin-