Combination Of Piston And Cylinder - Yamaha YZ125 2022 Owner's Service Manual

Diameter
53.957–53.972 mm (2.1243–
2.1249 in)
a
a. 17.5 mm (0.69 in) from the bottom edge of
the piston
e. If out of specification, replace the piston
and piston rings as a set.
f. Calculate the piston-to-cylinder clearance
with the following formula.
Piston-to-cylinder clearance =
Cylinder bore - Piston skirt diameter
Piston-to-cylinder clearance
0.040–0.045 mm (0.0016–0.0018
in)
g. If out of specification, replace the cylinder,
and replace the piston and piston rings as
a set.
EAM30547

COMBINATION OF PISTON AND CYLINDER

1. Check:
• Cylinder mark "a"
Cylinder mark "a"
A
B
C
D
CYLINDER HEAD, CYLINDER AND PISTON
Cylinder size
54.000–54.002 mm
(2.1260–2.1261 in)
54.004–54.006 mm
(2.1261–2.1262 in)
54.008–54.010 mm
(2.1263–2.1264 in)
54.012–54.014 mm
(2.1265–2.1265 in)
5-10
2. Check:
• Piston mark "a"
Piston mark "a"
(color)
A (red)
B (orange)
C (green)
D (purple)
3. Combination:
• Combine the piston and cylinder by the fol-
lowing chart.
Cylinder mark
A
B
C
D
TIP
When you purchase a cylinder, you cannot des-
ignate its size. Choose the piston that matches
the above chart.
Piston size
53.957–53.960 mm
(2.1243–2.1244 in)
53.961–53.964 mm
(2.1244–2.1246 in)
53.965–53.968 mm
(2.1246–2.1247 in)
53.969–53.972 mm
(2.1248–2.1249 in)
Piston mark (color)
A (red)
B (orange)
C (green)
D (purple)