Suzuki DR600S - Page 61

3-27 SERVICING ENGINE
NOTE:
The valve seat contact area must be inspected
after each cut.
1. Insert with a slight rotation, the solid pilot that
gives a snug fit.
2. Using the 45° cutter, descale and clean up the
seat with one or two turns.
3.
Inspect
the
seat
by
the
previous
seat
width
measurement
procedure.
If
the
seat
is
pitted
or
burned,
additional
seat
conditioning
with
the
45°
cutter
is
required.
CAUTION:
Cut
the
minimum
amount
necessary
from
the
seat
to
prevent
the
possibility
of
the
valve
stem
becoming
too
close
to
the
rocker
arm
for
correct
valve
contact
angle.
4.
After
the
desired
seat
position
and
width
is
achieved,
use
the
45°
cutter
very
lightly
to
clean
up
any
burrs
caused
by
the
previous
cutting
operations.
DO
NOT
use
lapping
com-
pound
after
the
final
cut
is
made.
The
finished
valve
seat
should
have
a
velvety
smooth
finish
and
not
a
highly
polished
or
shiny
finish.
This
will
provide
a
soft
surface
for
the
final
seating
of
the
valve
which
will
occur
during
the
first
few
seconds
of
engine
operation.
5.
Clean
and
assemble
the
head
and
valve
compo-
nents.
Fill
the
intake
and
exhaust
ports
with
gasoline
to
check
for
leaks.
If
any
leaks
occur,
inspect
the
valve
seat
and
face
for
burrs
or
other
things
that
could
prevent
the
valve
from
sealing.
WARNING:
Always
use
extreme
caution
when
handling
gasoline.
NOTE:
Be
sure
to
adjust
the
valve
celarance
after
reassembling
the
engine,
If
the
contact
area
is
too
low
or
too
narrow,
use
the
45°
cutter
to
raise
and
widen
the
contact
area.
Contact area too low
and too narrow on face
of valve
If the contact area is too high or too wide, use the
15° cutter to lower and narrow the contact area.
Contact area too high
and too wide on face of
valve
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