Honda CRF50F 2004-2015 Service Manual page 100

CYLINDER/PISTON INSPECTION
Inspect the cyli nder bore for wear or damage.
Measure the cvl inder I.D. in X and Y axis at three
levels.
Take the maximum reading t o deter mine the cylin-
der wear.
SERVICE LIMIT: 39.05 mm (1 .537 in )
Calculate the piston-Io-cylinder clearance.
Take a maximum reading to determine the clear-
ance.
Refer to page 8-6 for measurement of the piston
0 .0.
SERVICE UMIT: 0.15 mm (0.006 in )
Calculat e the taper and out of round at three levels
in
X
and Y axis. Take the maximum reading to
determine them.
SERVICE LIMITS:
Taper:
Out of round :
0.10 mm (0.004 in )
0.10 mm (0.004 in )
The cylinder must be rebored and an oversize pis·
ton fined if the service limits are exceeded .
The following oversize pistons are available:
0.25 mm (0.010 in )
0.50 mm (0.020 in )
The piston to cyl inder clearance for the oversize pis-
ton must be: 0.010 - 0.040 mm (0.0004 - 0.0016 in).
Inspect the top of the cyl inder for warpage.
SERVICE UMIT: 0.05 mm (0.002 in )
Remove any carbon deposits from the pist on ring
grooves, using an old piston ring as shown.
CYLINDER/PISTON
TOP
MIDDLE
BOTTOM
8-5