Maintenance After Break-In; Major Maintenance; Air Filter Maintenance - Yamaha WR450F 2021 Owner's Service Manual

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MAINTENANCE AFTER BREAK-IN

After a break-in, perform careful maintenance to
get ready for the next practice or race.
Refer to "PRE-OPERATION INSPECTION AND
MAINTENANCE" on page 3-6.
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MAJOR MAINTENANCE

1. For the engine
• Leaks around the engine
Check for pressure leaks from the cylinder
head or the cylinder, oil leaks from the crank-
case or the case cover, leaks from the cool-
ant system, and other leaks.
• Check that the valve, the cylinder head, the
cylinder, the piston, and the piston ring fit one
another, and that contact between the valve
and the cylinder head, and that between the
cylinder and the piston are correct.
• Engine oil change
Drain the oil, and check for dirt and foreign
materials such as metal chips. (If any foreign
material is mixed, disassemble and check the
crankcase.)
Pour the specified amount of the recom-
mended oil.
• Generator
Check for looseness in mounted areas of the
generator rotor and the stator coil assembly.
Check that the connector is not being discon-
nected.
• Silencer
Check the main body and stay for cracks.
Check for leaks.
• Mounting bolts and nuts
Check for looseness in mounted areas of
parts, as well as engine mounting bolts and
engine brackets.
2. For the chassis
• Check welds and mounted areas of the
frame, the swingarm, the link, the bracket,
and so on, for looseness and cracks.
• Wheel(s)
Check the wheel for runout. Check the spoke
for looseness.
• Brake(s)
Check the brake disc mounting bolt for loose-
ness.
Check that the reservoir contains the speci-
fied amount of brake fluid. Check for leaks.
• Cable
Grease and adjust cables.
• Drive chain
MAINTENANCE AFTER BREAK-IN
Lubricate the drive chain and adjust its ten-
sion.
• Fuel tank
Clean the inside of the fuel tank. Check for
leaks.
• Suspension
Check for oil leaks in the front fork or the rear
shock absorber. Check that the mounted
conditions are good.
• Sprocket
Check for looseness in the sprocket mounted
on the rear wheel.
• Mounting bolts and nuts
Check mounted areas for looseness.
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NOTICE
After a break-in or before each race, always
check the points shown in "TORQUE-
CHECK POINTS" for tightening torques and
retighten them.
• Greasing and oiling
Always grease or oil the specified points.
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AIR FILTER MAINTENANCE

Apply the Yamaha foam air filter oil or other qual-
ity foam air filter oil to the element. (Excess oil in
the element may adversely affect engine start-
ing.) Refer to "CLEANING THE AIR FILTER EL-
EMENT" on page 3-16.
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