Honda CRF250F 2023 Owner's Manual page 109

Drive Chain
4. Check the chain slider (2), chain guide slider
(3) and chain roller (4) for wear. If the chain
slider is worn to the bottom of the cutout (5),
have your dealer replace the slider.
Replace the chain guide slider if the chain is
visible through the wear inspection window
(6).
Replace the chain roller if it is smaller than
0.7 in (18 mm).
100
Servicing Your Honda
LEFT SIDE
(4)
(5)
(2) chain slider
(3) chain guide slider
(4) chain roller
5. Replace the drive chain if chain slack is
excessive when the rear axle is moved to the
farthest limit of adjustment. Excessive slack
indicates the chain is worn beyond its service
limit.
(2)
(3)
(6)
(5) cutout
(6) wear inspection window