Stihl BR 550, Руководство по обслуживанию

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43 BR 500, BR 550, BR 600
– Remover rocker arms/pushrods,
b 7.3
– Remove the crankshaft, b 7.9.3
Do not mix up the large inlet valve
and the small exhaust valve.
2
1
452RA125
VA
: Press valve spring retainer (1)
down and move it sideways so
that the valve stem is in the large
hole.
: Remove the spring retainer (1)
and together with the valve
spring (2).
– Take the valves out of the
cylinder.
: Check valve heads (1 and 2) for
damage.
: Check valve springs (3) for
damage.
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VA
3 1
2 3
– Inspect valve seats in cylinder
head for any damage. Replace
cylinder if necessary.
Install in the reverse sequence.
Valve spring retainer must engage
properly in groove of valve stem.
If the cylinder with piston has to be
replaced, first carry out the following
operations:
– Remove the muffler, b 7.6
– Remove the crankshaft, b 7.9.3
– Remove the rocker arms/
pushrods, b 7.3
– Remove the cam gear, b 7.5
– Remove the ignition module,
b 8.4
– Use combination wrench
4180 890 3400 to unscrew the
spark plug, check it for wear and
replace if necessary.
: Loosen the clamp (3) and remove
the manifold (2) with flange (1).
: Pull off the impulse hose (4).
452R
A
127
VA
2
3
1
4
7.9.6 Valves / Valve Springs 7.9.7 Upper Half of Crankcase
with Cylinder
RA_452_00_01_02.book Seite 43 Donnerstag, 16. Februar 2012 11:52 11