Honda CRF50F 2017 Owner's Manual page 81

4. Check the chain slider (2) for wear.
If the ridge (3) in the centre of the slider
is worn, have your dealer replace the
chain slider.
(3)
(3)
(2) Chain slider
(3) Ridge
70
(2)
5. Measure a section of the drive chain to
determine whether the chain is worn
beyond its service limit. Remove the
drive chain and measure the distance
between a span of pins from pin centre to
pin centre. If the distance exceeds the
service limit, the chain is worn out and
should be replaced.
New Chain:
978 mm (38.5 in)
Ser vice Limit:
997 mm (39.3 in)
Measure a span of : 78 pins.