Honda CRF450R 2020, Owner'S Manual & Competition Handbook

Page: 127 / 199

Drive Chain
122
Servicing Your Honda
Drive Chain
Refer to Important Safety Precautions on page 23.
The service life of the chain depends on proper
lubrication and adjustment. Poor maintenance can
cause premature wear or damage to the drive chain
or sprockets.
When the motorcycle is ridden on unusually dusty
or muddy tracks, more frequent maintenance will
be necessary.
Before servicing your drive chain, turn the engine
OFF and check that your transmission is in neutral.
1. Turn the engine off, raise the rear wheel off the
ground by placing an optional workstand or
equivalent support under the engine and shift
the transmission into neutral.
2. Check the drive chain slack (1) in the upper
drive chain run midway between the drive
sprocket (2) and driven sprocket (3). Drive
chain slack should allow the following vertical
movement by hand:
1 3/8 – 1 3/4 in (35 – 45 mm)
3. Check drive chain slack at several points along
the chain. The slack should remain constant. If
it isn’t, some links may be kinked and binding.
Lubricating the chain will often eliminate
binding and kinking.
Excessive chain slack may allow the drive chain to
damage the engine cases.
4. Inspect the drive chain for:
• damaged rollers
• loose pins
• dry or rusted links
• kinked or binding links
• excessive wear
Replace the drive chain (page 124) if it has
damaged rollers, loose pins, or kinks that cannot be
free. Lubricate the drive chain (page 123) if it
appears dry or shows signs of rust. Lubricate any
kinked or binding links and work them free.
Adjust chain slack if needed (page 123).
1. Check the chain slider (1) for wear.
Replace it if below the service limit.
SERVICE LIMIT:
upper side:
0.2 in (5 mm)
lower side:
0.10 in (2.5 mm)
2. Check the chain guide slider (2) for wear.
Replace the guide slider if it is worn to the
bottom of the wear limit (3).
Inspection
(1) drive chain slack (3) driven sprocket
(2) drive sprocket
(2) (3)
(1) 1 3/8 – 1 3/4 in (35 – 45 mm)
Drive Chain Sliders
(1) chain slider
(2) chain guide slider (3) wear limit
0.2 in
(5 mm)
0.10 in
(2.5 mm)
(1)
(1)
(2)
(3)
(3)