Honda CBR125R Owner's Manual page 267

BIG END RADIAL CLEARANCE
Measure the radial clearance of the connecting rod
big end.
SERVICE LIMIT: 0.05 mm (0.002 in)
TIMING SPROCKET
Check the timing sprocket teeth for wear or damage.
If the timing
sprocket teeth are
If you are replacing the timing sprocket, align the
worn or damaged,
center of the sprocket teeth with the center of the
check the cam
woodruff key groove as shown.
chain, tensioner
and cam sprocket.
CRANKSHAFT BEARING
Turn the inner race of the right crankshaft bearing
RIGHT SIDE:
with your finger.
The bearing should turn smoothly and quietly.
Also check that the outer race fits tightly in the
crankcase.
Turn the outer race of the left crankshaft bearing
LEFT SIDE:
with your finger.
The bearing should turn smoothly and quietly.
Also check that the inner race fits tightly on the
crankshaft.
Remove and discard the bearing if the races do not
Replace the bearing
turn smoothly, quietly, or if they fit loosely in the
in pairs.
crankcase and crankshaft.
For crankshaft bearing replacement (page 12-18).
BALANCER BEARING
Turn the inner race of the right crankshaft bearing
with your finger.
The bearing should turn smoothly and quietly.
Also check that the outer race fits tightly in the
crankcase.
Remove and discard the bearing if the races do not
turn smoothly, quietly, or if they fit loosely in the
crankcase and crankshaft.
For balancer bearing replacement (page 12-19).
CRANKSHAFT/BALANCER/TRANSMISSION
TIMING SPROCKET
LEFT SIDE shown:
GROOVE
12-9