Crankcase; Crankshaft - Stihl MS 270 User Manual

Position the piston rings so that
the radii at the ring gaps meet at
the fixing pins (arrows) in the
piston groove when the rings are
compressed.
MS 270, MS 280
6.7

Crankcase

6.7.1

Crankshaft

Removing
– Remove the chain catcher
– see 5.2.
– Remove the chain brake
– see 5.4.2.
– Remove the cylinder –
– Drain the oil tank.
– remove the oil pump –
– Remove the flywheel –
3
1
2
Lift the crankshaft (1) with
piston (2) out of the
crankcase (3).
– Pull off the oil seals.
Check the ball bearings (arrows)
on crankshaft (1) for damage and
replace if necessary.
If the ball bearings are damaged,
remove them as follows:
see 6.5.1.
see 11.4.
see 7.3
Heat the ball bearing (arrow) to
about 50°C and pull it off the
crankshaft.
The crankshaft and connecting rod
form an inseparable unit. This
means that the crankshaft must
always be replaced as a complete
unit in the event of damage to either
1
part.
If the crankshaft has to be replaced,
remove the piston – see 6.5.1.
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