Checking The Cylinders And Pistons - Yamaha YZF-R1 98 Service Manual

CONNECTING RODS AND PISTONS
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EB404403

CHECKING THE CYLINDERS AND PISTONS

The follow ing procedure applies to all of
the cylinders and pistons.
1. Check:
• piston w all
• cylinder w all
scratches → Replace the
Vertical
crankcases, and the piston and piston
rings as a set.
2. M easure:
• piston-to-cylinder clearance
a. M easure cylinder bore " C" w ith the
cylinder bore gauge.
NOTE:
M easure cylinder bore " C" by taking
side-to-side and front-to-back m easure-
m ents of the cylinder. Then, find the
average of the m easurem ents.
Cylinder bore gauge
90890-03017
Cylinder bore "C"
M ax. taper "T"
Out of round "R"
"C"= maximum of D
"T" = maximum of D
mum of D or D
5
"R" = maximum of D
mum of D , D or D
2 4
b. If out of specification, replace the
crankcases, and the pistons and pis-
ton rings as a set.
c. M easure piston skirt diam eter " P"
w ith the m icrom eter.
M icrometer
90890-03008
a 5 m m from the bottom edge of the pis-
ton
Standard
d. If out of specification, replace the pis-
ton and piston rings as a set.
ENG
74.000 ~ 74.010 mm
0.05 mm
0.05 mm
~ D
1 6
, or D – maxi-
1 2
6
, D or D – mini-
1 3 5
6
Piston size "P"
73.955 ~ 73.970 mm