34 MS 311, MS 391
– Lubricate the piston, piston rings
and cylinder wall with oil.
: Position the piston rings so that
the radii at the ring gap meet at
the fixing pin in the piston groove
(arrows) – there is otherwise a
risk of ring breakage.
– Line up the piston with crankshaft
before fitting them in the cylinder.
Viewed from the exhaust
port (arrow), the long crankshaft
stub (1) must be on the right.
533RA104 TG
4903RA075 TG
1
When properly aligned, the piston
rings are compressed by the
cylinder's taper.
: Carefully push the piston with
crankshaft (1) into the cylinder.
– Place the crankshaft with
bearings and oil seals in the
bearing seats, making sure the oil
seals are firmly against their
stops (arrows) in the cylinder.
4903RA076 TG
1
4903RA090 TG
– Inspect and clean the sealing
face on the engine housing and
remove any gasket residue,
b 14
The sealing faces must be in perfect
condition. Always replace
components with damaged sealing
faces.
: Apply sealant to the groove in the
sealing face, b 14
– Hold the crankshaft (1) steady.
: Fit the cylinder (2) with
crankshaft (1) in the engine
housing.
4903RA078 TG
4903RA079 TG
1
2