Yamaha YZ250 2021, Owner'S Manual

Page: 23 / 148

MAINTENANCE AFTER BREAK-IN
1-13
EAM20124
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 3-4.
EAM30199
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 cylinder, the piston, and the
piston ring fit one another, and that contact
between the cylinder and the piston are cor-
rect.
•
Transmission 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
transmission.)
Pour the specified amount of the recom-
mended oil.
• Carburetor
Disassemble the carburetor and clean the
small holes, blowing them with compressed
air.
• CDI magneto
Check for looseness in mounted areas of the
rotor and the stator.
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
Lubricate the drive chain and adjust its ten-
sion.
• Fuel tank
Clean the inside of the fuel tank and the fuel
cock. 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.
NOTICE
ECA25831
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 ELE-
MENT” on page 3-8.