Shibaura ST318, Руководство по ремонту

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(2) Piston ring
➀ Replace worn out or damaged piston ring, if any.
➁
Insert a ring at a right angle to the least worn out
skirt of a cylinder, measure the clearance of ring
end gap with a thickness gauge and replace if the
end gap exceeds the service limit.
Piston ring end gap (mm)
S773
Standard assembling
value
Service limit
Top ring 0.2 – 0.35 1.0
Second ring 0.15 – 0.20 1.0
Oil ring 0.15 – 0.35 1.0
Piston ring end gap (mm)
S773L
Standard assembling
value
Service limit
Top ring 0.2 – 0.35 1.0
Second ring 0.15 – 0.20 1.0
Oil ring 0.15 – 0.35 1.0
➂
Measure the clearance between the piston ring
grove and ring and replace if the service limit is
exceeded.
➃ When the cylinder is replaced with an over size one,
use a piston ring set of over size accordingly.
Piston kit composed of piston and piston rings are
available.
Piston kit
Model Size Part code No.
S753
STD. 115017140
O.S. 0.5
115017150
O.S. 1.0 115017160
S773
STD. 115016990
O.S. 0.5 115016980
S773L
STD. 115017460
O.S. 0.5 115017450
➄ Piston ring installing procedure
Install the piston ring to the piston as shown in the
right figure.
(3) Piston pin
Measure the outside diameter of the piston pin and
replace if the service limit is exceeded.
Piston ring end gap (mm)
S753
Standard assembling
value
Service limit
Top ring
0.2 – 0.35 1.0
Second ring 0.15 – 0.20 1.0
Oil ring
0.15 – 0.35 1.0
T123
Clearance between piston ring groove and ring (mm)
Standard assembling
value
Service limit
Top ring 0.06 – 0.1 More than 0.25
Second ring 0.05 – 0.09 More than 0.25
Oil ring 0.02 – 0.06 More than 0.15
Model
Piston ring size Part code No.
S753
STD. 115107201
O.S. 0.5 115107204
O.S. 1.0 115107206
S773·S773L
STD. 115107900
O.S. 0.5 115107430
T124
Piston pin outside dia. (ø)
Standard assembling value Service limit
20.998 – 21.002 Less than 20.98