Piston Ring Installation - Polaris 1999 Sportsman 400 Service Manual

130
exceeds the spec ification in Table 4. If the gap on a
new compression ring is smaller than specified.
place a sma ll file in a vise (Figu re 147), grip the ends
of the ring
with
two lingers and enlarge the gap.
Piston Ring
l nsta lla t lun
1. If
new rings arc
installed, the cylinder must be
de glazed or honed. T his w ill hel p to scat the new
rings. If ncccssary. refer honing service to a Polaris
dealership or motorcycle repairshop. A fter honing,
measure the end gap of each ri ng and compare to
specifications in Tab le 4 .
e__
~
C HA PT ER FOUR
NOTE
If/he
cylinder was deg lazed
or honed.
clean the cy linde r as d escribed under
Cylinde r Block Insp ect ion in this
chapter.
2. Clean the piston and rings. Dry with com pressed air.
3. Install piston rings as foll ows:
NOTE
lnstall thr
piston
rillgs-jirst the bot-
tom , then the middl e. then tire
lop
ring
by carefully sp reading the ends by
hand (Fig u re /44)
IIl1d
s lipping the
rings Ol' e r
the
top of
the piston. Re-
mem ber that the piston ri ngs mus t be
installed witlt the marks
0 11
the m fac-
ing
lip toward the tap a/the
piston. ln-
correctly installed piston rings can
wear rapidly and/or allow oil to es-
cape past/hem.
a. Install the oil ring assemb ly into the bottom ring
groove. First install the expander spacer so that
the ends bun together. Do not overlap the ends.
Then install the lop and bottom ring rails.
b. Install the compression rings with the manu-
facturer 's mark
facing
up.
NOTE
When installing a ftermarket piston
rings. fiJI/ow the
manufacturer
s
di-
rections .
c. Install the second or middle co mpress ion
rmg,
d . Install the top co mpress ion rin g.
4. Make sure the rin gs are sea led co mpletely in
their grooves all the way around the piston and that
II
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gauge