Yamaha MT-09 2021, Service Manual

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5-21
CAMSHAFTS
EAS30258
CHECKING THE TIMING CHAIN AND
CAMSHAFT SPROCKET
1. Check:
• Timing chain
Damage/stiffness
→
Replace the timing
chain and camshaft and camshaft sprocket
as a set.
2. Check:
• Camshaft sprocket
More than 1/4 tooth wear “a”
→
Replace the
camshaft sprockets and the timing chain as a
set.
EAS30265
CHECKING THE TIMING CHAIN GUIDES
1. Check:
• Timing chain guide (intake side)
• Timing chain guide (top side)
Damage/wear
→
Replace the defective
part(s).
EAS30266
CHECKING THE TIMING CHAIN TENSIONER
1. Check:
• Timing chain tensioner
Cracks/damage/rough movement
→
Re-
place.
a. Using the valve spring compressor “1”,
push and insert timing chain tensioner rod
“2” into the timing chain tensioner housing.
TIP
Push the timing chain tensioner rod in direction
“a”, and turn the timing chain tensioner body “3”
in direction “b” until the circlip fits into the groove.
b. Lock the timing chain tensioner rod by set-
ting the circlip “4” to groove “5” while push-
ing the timing chain tensioner rod.
c. Push the timing chain tensioner rod “c”.
d. If the circlip does not unlock even though
you press the timing chain tensioner rod in
the “c” direction, rotate the timing chain ten-
sioner rod clockwise.
e. Make sure that the timing chain tensioner
rod comes out “d” of the timing chain ten-
sioner housing smoothly. If there is rough
movement, replace the timing chain ten-
sioner.
a. 1/4 tooth
b. Correct
1. Timing chain
2. Camshaft sprocket
G088949
a
1
2
b
G088950
2
3
1
1
a
b
5
4