Yanmar YSE8 Service Manual page 28

DisassemblY
1)
Detach the cylinder head from the engine, remove thoroughly carbon from com-
bustion surfaces of the cylinder heed aDd from the internal surlaces of the pre-
combustion cha.mber, and then inspect arld service the va]ves.
2)
Remove the split tapper collets by pressing each spring holder with spanner' They
will come off to\'rard the combustion chanber.
\
:1.
a.
?
Checking & Servicing
Check point
YSES
YSElZ
Intake
1042t1
- 1 1 1 0 0
104511
- 1 1 1 0 0
Exhaust
valve
L042ll
- 1 1 1 0 0
1 0 4 5 1 1
- 1 1 1 1 0
Scmtches or wear
on intake/exhaust
valve seating
sudace.
Renew if stepped wear
or deep scratches.
Fit if poor fitting ot
shallow scratches.
(Refer to next column. )
Note: Seat width should
be less than 2 mm.
Lap if scratched or worn to a broader \ridth than Specified.
Lapping method
(If heavily wor.n or scratched, correct with a seat cutter. )
.:i
1.
Lap till scratches are gone
with coarse compound, then
with fine compound.
For finishing, use oil .
wash off the lapping compound.
Apply red lead to the seat and check fitting aterthe lappin
operauon.
After that, be sure to apply oil to seat.
Scratches or
wear on cylinder
head valve seat.
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