Checking The Camshaft Sprocket And Timing Chain Guide; Checking The Timing Chain Tensioner - Yamaha YZF-R15 Service Manual

2. Check:
• Cylinder head
Damage/scratches → Replace.
• Cylinder head water jacket
Mineral deposits/rust → Eliminate.
3. Measure:
• Cylinder head warpage
Out of specification → Resurface the cylinder
head.
Warpage limit
0.03 mm
s s s s s s s s s s s s s s s s s s s s s s s s s s
a. Place a straightedge "1" and a thickness
gauge "2" across the cylinder head.
b. Measure the warpage.
c. If the limit is exceeded, resurface the cylinder
head as follows.
d. Place a 400–600 grit wet sandpaper on the
surface plate and resurface the cylinder head
using a figure-eight sanding pattern.
NOTE:
To ensure an even surface, rotate the cylinder
head several times.
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CHECKING THE CAMSHAFT SPROCKET
AND TIMING CHAIN GUIDE
1. Check:
• Camshaft sprocket
More than 1/4 tooth wear "a" → Replace the
camshaft sprocket, timing chain and crank-
shaft as a set.
a. 1/4 tooth
b. Correct
1. Timing chain roller
2. Camshaft sprocket
2. Check:
• Timing chain guide (exhaust side)
Damage/wear → Replace.

CHECKING THE TIMING CHAIN TENSIONER

1. Check:
• Timing chain tensioner
Cracks/damage/rough movement → Re-
place.
a. Lightly press the timing chain tensioner rod
into the timing chain tensioner housing by
hand.
NOTE:
While pressing the timing chain tensioner rod,
wind it clockwise with a thin screwdriver "1" until
it stops.
b. Remove the screwdriver and slowly release
the timing chain tensioner rod.
c. Make sure that the timing chain tensioner rod
comes out of the timing chain tensioner hous-
ing smoothly. If there is rough movement, re-
place the timing chain tensioner.
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CYLINDER HEAD
1