Cylinder - Yamaha YZ85( P) /LC Owner's Service Manual

CYLINDER HEAD, CYLINDER AND PISTON
2. Inspect:
Cylinder head water jacket
Crust of minerals/rust
Cylinder head warpage
Out of specification
Warpage measurement and resurfacing
steps:
Attach a straightedge 1 and a thickness
5PA40450
gauge 2 on the cylinder head.
Measure the warpage.
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-
5PA40460
tern.
NOTE:
Rotate the cylinder head several times to
avoid removing too much material from one
side.

Cylinder

1. Clean:
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
CAUTION:
Do not rebore the cylinder.
5PA40480
4 - 18
ENG
Remove.
Re-surface.
Warpage limit:
0.03 mm (0.012 in)
Repair or replace.