Polaris 1999 Sportsman 400 Service Manual page 108

102
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C HA P T E R FOU R
5. Inspect each rocker ann pad (A, Figu re 27)
wh ere
it
contacts the camshaft lo be and where the
adj uster ( B, Figure 27 ) contacts the valve stern .
Check for scratches, flat spots, uneven wear and
scori ng and rep lace ifn ccessa ry.
NOTE
The valve adjuster screw is hardened.
It cannot be re-faced ifdamaged.
6. lnspcct the va lve adj uster sc rew for n at spots,
crac ks or ot he r da mage . Inspec t the locknuts for
damage. Rep lace the va lve adj uster screw and
locknuts if necessary.
7. Inspect the rocker arm sha ll surface (Fig u re 28)
for wear, scori ng, cracks or ot he r damage and re-
place if necessary.
8. Unscrew the rocker shaft retaining screw and
separa te the shaft from the sup po rt (Figu re 29 ).
9. Inspect rock er ann bores (Figure 30 ) and the
shaft suppo rt bore (F igu re 31 ) for wear or scoring.
10. Measure the rocker ann bore diameter with a
snap ga uge ( Figu re 32 ). Record the dimen sion .
II. Measure the rocker ann shaft outside diameter
with a micrometer (F igure 33). Record the dimension .
12. Calculate the rocke r arm-to -shaft clearance as
follows:
a. Subtrac t the rocker arm shaft diameter (Step II )
from the rocker ann bore diameter (Step 10).
b. Replace the rocker ann and/or sha ft if the
clearanc e exceeds the service lim it in Ta b le 4.
13. Repeat for the ot her rocker ann.
14. Apply clean engine oil to all slidin g parts and
install the rocker arms onto the shaft. then install the
support . Refe r to Figure 34 for the correct place-
me nt o f all parts on the shaft.
15. Install the rocker ann assembly as described in
this chapter.
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