Checking The Cylinder Head; Checking The Distribution - SHERCO 2015 450 SEF-R Workshop Manual

Checking individual parts
❱❘ Checking the cylinder head
Cylinder head inspection for warping:
• Place a ground ruler [A] on the lower surface of
the cylinder head at different positions, and mea-
sure the warping by inserting a thickness gauge
between the straightedge and the gauge head.
If the warping exceeds the tolerated limit, repair the
adjusting surface. Replace the cylinder head if the
adjusting surface is seriously damaged.
Warping of the cylinder head:
Limit = 0.05 mm
Valve/guide clearance:
Intake:
Minimum clearance: 0.02 mm
Maximum Clearance: 0.045 mm
Exhaust:
Minimum clearance: 0.04 mm
Maximum Clearance: 0.065 mm
❱❘ Checking the distribution
• Clean all parts.
• Visually inspect the drive chain: check for any
hard spot, resistance, or wear. If any, it must be
changed.
• Visually inspect the distribution drive pinion.
Change if necessary.
• Visually inspect distributions guide plates:
change them if necessary.
• Visually inspect the pinion (1); replace if neces-
sary.
• Check that the needle bearings fit tight when
the pinion (1) is mounted on its axis.
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