Yamaha YZ85(V), Owner'S Service Manual

Page: 234 / 508

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ENG
2. Inspect:
●
Cylinder head water jacket
Crust of minerals/rust
→
Remove.
●
Cylinder head warpage
Out of specification
→
Re-surface.
Warpage measurement and resurfacing
steps:
●
Attach a straightedge
1
and a thickness
gauge
2
on the cylinder head.
●
Measure the warpage.
Warpage limit:
0.03 mm (0.012 in)
●
If the warpage is out of specification,
resurface the cylinder head.
●
Place # 400 ~ 600 grit wet sandpaper
3
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.
5PA40450
5PA40460
Cylinder
1. Eliminate:
●
Carbon deposits
Use a rounded scraper
1
.
NOTE:
Do not use a sharp instrument. Avoid scratch-
ing the aluminum.
5PA40470
2. Inspect:
●
Cylinder inner surface
Use # 400 ~ 600 grit wet sandpaper.
Score marks
→
Repair or replace.
CAUTION:
Do not rebore the cylinder.
5PA40480
CYLINDER HEAD, CYLINDER AND PISTON