Shibaura ST330, Workshop Manual

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36
(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)
N843
Standard assembling
value
Service limit
Top ring
0.2 – 0.35 1.0
Second ring
0.2 – 0.4 1.0
Oil ring 0.2 – 0.8 1.2
➂
Measure the clearance between the piston ring grove
and ring and replace if the service limit is exceeded.
➃ Piston kit composed of piston and piston rings are
available.
Piston kit
Model Size Part code No.
N843 STD
115017541
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.
123Y
Clearance between piston ring groove and ring (mm)
N843
Standard assembling
value
Service limit
Top ring
0.07 – 0.11 0.25
Second ring
0.04– 0.08 0.25
Oil ring 0.03 – 0.13 0.25
Model Piston ring size Part code No.
N843 STD. 115107970
124Y
Piston pin outside dia. (ø)
Standard assembling value Service limit
N843
27.994
－
28.0
27.97