ENGLISH
10
S
HAFT SEAL RING OF THE CRANKSHAFT
7
Insert a new shaft seal ring from outside, the sealing lip facing inwards. The seal ring
must be 2 mm (0.08 in.) below the edge of the housing.
4.3 Piston
When intending to reinstall a used piston, perform the following checks:
– Check the piston bearing surface for signs of wear (seizing of the piston).
Superficial grooves can be removed using a fine-grained abrasive block.
– The piston rings should not stick in their grooves. To clean the grooves, use an
old piston ring or abrasive paper.
– The piston-ring locking devices
1
must fit tightly into the piston and should not
be worn.
– The piston pin should not be discolored or significantly grooved.
4.3.1 Checking the piston ring end gap
– Check the piston rings for signs of wear (grooves).
– Check the piston ring end gap
B
.
– Align the piston ring with the piston approximately 10 mm (0.4 in.) below the
upper cylinder edge.
– Use a feeler gauge to measure the end gap
B
.
E
ND GAP
:
MAX
. 0.55
MM
(0.022
IN
.)
I
F THE END GAP EXCEEDS THIS LIMIT
,
CHECK PISTON AND CYLINDER FOR WEAR
(
FOR WEAR
LIMITS REFER TO THE TECHNICAL SPECIFICATIONS
). I
F BOTH PISTON AND CYLINDER WEAR ARE
WITHIN THE ADMISSIBLE LIMITS
,
REPLACE THE PISTON RINGS
.
4.4 Measuring piston and cylinder, piston fitting clearance
– To determine cylinder wear, measure the cylinder, applying a micrometer to the
middle of the bearing surface.
– Measure the cylinder diameter along both the x-axis and y-axis to determine ova-
lity, if any.
– The piston is measured at the piston skirt at a right angle to the piston pin as
shown in the illustration.
– The piston fitting clearance is the cylinder diameter minus the piston diameter.
P
ISTON FITTING CLEARANCE
(S5-E) :
MAX
. 0.070
MM
(0.0028
IN
.)
P
ISTON FITTING CLEARANCE
(S5-T/S5-GS) :
MAX
. 0.028
MM
(0.001
IN
.)
x
y
7
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