Yamaha YZ-Serie Fahrer- Und Wartungshandbuch Seite 232

CYLINDER HEAD, CYLINDER AND PISTON
5PA40450
5PA40460
5PA40470
5PA40480
2. Inspect:
Cylinder head water jacket
G
Crust of minerals/rust → Remove.
Cylinder head warpage
G
Out of specification → Re-surface.
Warpage measurement and resurfacing
steps:
Attach a straightedge 1 and a thickness
G
gauge 2 on the cylinder head.
Measure the warpage.
G
Warpage limit:
0.03 mm (0.012 in)
If the warpage is out of specification,
G
resurface the cylinder head.
Place # 400 ~ 600 grit wet sandpaper 3
G
on the surface plate, and re-surface the
head 4 using a figure-eight sanding pat-
tern.
NOTE:
Rotate the cylinder head several times to
avoid removing too much material from one
side.
Cylinder
1. Eliminate:
Carbon deposits
G
Use a rounded scraper 1.
NOTE:
Do not use a sharp instrument. Avoid scratch-
ing the aluminum.
2. Inspect:
Cylinder inner surface
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Use # 400 ~ 600 grit wet sandpaper.
Score marks → Repair or replace.
CAUTION:
Do not rebore the cylinder.
4 - 18
ENG