Bearings / Crankcase - Stihl MS 261 User Manual

1
: Fit the retaining ring (1).
– Check and install the piston,
b 6.7
– Check and install the cylinder,
b 6.5
– Reassemble all other parts in the
reverse sequence.
6.6.1

Bearings / Crankcase

Each half of the crankcase can be
replaced separately if it is damaged.
New crankcase halves are supplied
with the main parts preassembled
– see the parts list.
Parts not supplied with the new
crankcase must be transferred from
the original crankcase – check the
parts and replace if necessary.
If a new crankcase is installed, the
machine's serial number must be
stamped on it with 2.5 mm figure
stamps.
MS 261, MS 261 C
If the original crankcase is used
again, replace the oil seals and ball
bearings, remove any gasket
residue and clean the sealing
surfaces thoroughly. The sealing
faces must be in good condition and
clean to guarantee a perfect seal.
Inspect both halves of the
crankcase for cracks and all sealing
faces for signs of damage.
– See also Troubleshooting, b
– Remove the crankshaft, b 6.6
– Wear protective gloves
to reduce risk of burn injury.
Ignition side of crankcase
: Use a punch to carefully drive out
the oil seal.
: Check and clean the crankcase
or replace if necessary.
– If this half of the crankcase is in
order, install a new ball bearing.
1
– Heat the area of the bearing seat
b 3.7
to about 160°C (320°F).
The bearing (1) drops out as soon
as this temperature is reached.
Installing
– Heat the area of the bearing seat
to about 160°C (320°F).
– Position the ball bearing so that
its open side (balls visible) faces
the inside of the crankcase.
: Push the ball bearing home as far
as stop.
This operation must be carried out
quickly because the bearing
absorbs heat and begins to expand.
– Check that ball bearing is
properly seated. If necessary,
use press arbor 1118 893 7200 to
press the bearing fully home.
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