Yanmar 4LHA-HTP Operation Manual page 344

Chapter 2 Basic Engine
5. Piston and Piston Pins
1st compression ring
a.
a
T O
m
2
O
2nd compression ring
(5) The oil ring is provided with a coil expander. The coil
expander joint should be opposite (staggered 180°) the
oil ring gap.
Gap
Direction of
piston pin
Joint of
coil expander
2-24
, 4LHA Series