Piston Pin Inspection; Piston Rings, Piston And Cylinder Installation - Yamaha SR125 1997 Service Manual

CYLINDER AND PISTON
EB402120

PISTON PIN INSPECTION

1. Inspect:
: Piston pin
Blue discoloration/grooves ! Replace, then
inspect the lubrication system.
2. Measure:
: Piston pin-to-piston clearance
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Measurement steps:
: Measure the piston pin outside diameter a .
If out of specification, replace the piston pin.
Outside diameter (piston pin):
: Measure the piston inside diameter b .
: Calculate the piston pin-to-piston clearance
using the following formula:
Piston pin-to-piston clearance =
Bore size (piston pin)
Outside diameter (piston pin)
: If out of specification, replace the piston.
Clearance (piston pin-to-piston):
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EB404184
PISTON RINGS, PISTON AND CYLINDER
INSTALLATION
1. Install:
: Top ring 1
: 2nd ring 2
: Side rails (oil ring) 3
: Expander spacer (oil ring) 4
NOTE:
: Make sure to install the piston rings so that the
manufacturer's marks or numbers are located
on the upper side of the rings.
: Lubricate the pistons and piston rings liberally
with engine oil.
4-24
ENG
14.978 14.992 mm
<Limit> 14.975 mm
–
b
0.010 0.035 mm
a