Breather Hose; Cylinder Head Decarbonization; Adjusting The Valve Clearance - Yamaha MX250 Service Manual

PERIODIC MAINTENANCE
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BREATHER HOSE

1.
Check:
• Breather hose "1"
Crack/damage  Replace.
Poor connection  Connect.
1

CYLINDER HEAD DECARBONIZATION

1.
Remove:
• Cylinder head assembly
(Refer to "CYLINDER HEAD COVER, CYLINDER
HEAD" on page 3-22)
2.
Eliminate:
• Carbon deposits
(Refer to "CHECKING THE CYLINDER HEAD" on
page 3-24)
3.
Install:
• Cylinder head assembly
(Refer to "INSTALLING THE CYLINDER HEAD
ASSEMBLY" on page 3-25)

ADJUSTING THE VALVE CLEARANCE

1.
Remove:
• Spark plug cap "1"
• Spark plug "2"
NOTICE
Before removing the spark plug, use compressed air
to clean the cylinder head cover to prevent dirt from
falling into the engine.
4
2.
Remove:
• Breather hose "3"
• Cylinder head cover "4"
• Cylinder head cover gasket
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