Yanmar 3TNV Series Service Manual page 109

4. Disassembly, Inspection and Reassembly of Engines
Point6: Piston pin and rings
[Disassemble]
Using the piston ring replacer (see 4.1.2 in
Chapter 4), remove the piston rings.
Remove the circlip and remove the piston pin by
pushing it out.
[Reassemble]
Install each piston ring on the piston, with the
punched manufacturer's mark facing upward.
[Reassemble]
The piston ring joints shall be staggered at by
120° intervals. Do not position the top ring joint
vertical to the piston pin. The coil expander joint
shall be opposite to the oil ring joint.
[Reassemble]
When installing the piston pin to the rod and
piston, the punched match mark on the big end of
the connecting rod shall be opposite to the size
mark on the piston top.
[Reassemble]
Install the piston in the cylinder clock with the
punched mark on the big end of the rod on the
nozzle side. (The embossed mark at the
connecting rod I-beam section shall be on the
flywheel side.)
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