Crankshaft; Inspection And Repair; Cylinder Head; Cylinder - Yamaha YT175J 1982 Service Manual

Crankshaft
Remove crankshaft assembly with the
crankcase separating tool.
3-7
INSPECTION AND REPAIR
Cylinder head
1. Remove spark plug.
2. Using a rounded scraper, remove car-
bon deposits from combustion
chamber. Take care to avoid damaging
spark plug threads. Do not use a sharp
instrument. Avoid scratching the com-
bustion chamber surface.
3. Place on a surface plate. There should
be no warpage. Correct by re-surfacing
as follows:
Place 400 - 600 grit wet sandpaper on
surface plate and re-surface head using
a figure-eight sanding pattern. Rotate
head several times to avoid removing
too much material from one side.
Cylinder
1. Hone cylinder bore using a hone with
fine stones. Hone no more than required
to remove all wear marks.
2. Using a Cylinder Gauge set to standard
bore size, measure the cylinder.
Measure front-to-rear and side-to-side at
top, center and bottom just above ex-
haust port. Compare minimum and max-
imum measurements. If over tolerance
and not correctable by honing, rebore to
next over-size.