Checking The Piston Rings - Yamaha FZ09E Service Manual

CONNECTING RODS AND PISTONS
and front-to-back measurements of the cylinder.
Then, find the average of the measurements.
Bore
78.000-78.010 mm
(3.0709-3.0713 in)
Taper limit
0.050 mm (0.0020 in)
Out of round limit
0.050 mm (0.0020 In)
"C" = maximum of D
1
- D
6
Taper limit = maximum of D
1
or D
2
-
maxi-
mum of Ds or Ds
Out of round limit = maximum of D
1 ,
D3 o r D
5
- minimum of D
2
,
D
4
or D5
~
... 04 ... -- --- -
•
b. If out of specification, replace the cylinder,
and replace the piston and piston rings as a
set.
c. Measure piston skirt diameter "P" with the mi-
crometer.
a
Piston
Diameter
77.975-77.990 mm
(3.0699-3.0705 In)
p
a. 12.0 mm
(0.47 in)
from the bottom edge of
the piston
d. If out of specification, replace the piston and
piston rings as a set.
e. Calculate the piston-to-cylinder clearance
with the following formula.
Piston-to-cylinder clearance = Cylinder bore
"C" - Piston skirt diameter "P"
Piston-to-cylinder clearance
0.010-0.035 mm (0.0004-0.0014
in)
Limit
0.150 mm (0.0059 in)
f. If out of specification, replace the cylinder,
and replace the piston and piston rings as a
set.
......
,,.
CHECKING THE PISTON RINGS
1. Measure:
• Piston ring side clearance
Out of specification -> Replace the piston
and piston rings as a set.
TIP ~~~~~~~~~~~~~~­
Before measuring the piston ring side clearance,
eliminate any carbon deposits from the piston
ring grooves and piston rings .
Piston ring
Top ring
Ring side clearance
0.030-0.065 mm (0.0012-0.0026
in)
Limit
0.115 mm (0.0045 in)
2nd ring
2. Install:
Ring side clearance
0.020-0.055 mm (0.0008-0.0022
in)
Limit
0.115 mm (0.0045 in)
• Piston ring
(into the cylinder)
5-62