Honda 2003 NPS50 Ruckus Service Manual page 191

Set the crankshaft on V-blocks and read the runout
points as shown, using a dial indicator. Actual
run out is 1/2 of total indicator reading.
SERVICE LIMIT: 0.05 (0.002 in)
mm
Turn the outer race of the crankshaft bearings with
your finger. The bearing should turn smoothly and
quietly. Also check that the bearing inner race fits
tightly on the crankshaft.
Replace the crankshaft assembly if the bearings do
not turn smoothly, quietly, or if they fit loosely on
the crankshaft.
Set the crankshaft on a turning stand or V-blocks
and measure the runout using a dial indicator.
SERVICE LIMIT: 0.10 (0.0039 in)
mm
Check the timing sprocket teeth for wear or damage.
CRANKSHAFT /PISTON/CYLINDER
55 mm
50 mm
1 3-7