Yamaha Fz6 N Service Manual

CAMSHAFTS
5-10
EAS23810
REMOVING THE CAMSHAFTS
1. Remove: Pickup rotor cover
Refer to PICKUP ROTOR on page 5-33.
2. Align:  “T” mark “a” on the pickup rotor
(with the crankcase mating surface “b”)
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a. Turn the crankshaft clockwise.
b. When piston #1 is at TDC on the compres- sion stroke, align the “T” mark “a” on the 
pickup rotor with the crankcase mating sur-
face “b”.
NOTE:
TDC on the compression stroke can be found 
when the camshaft lobes are turned away from 
each...

CAMSHAFTS
5-11
8. Remove: Camshaft sprockets
EAS23850
CHECKING THE CAMSHAFTS
1. Check: Camshaft lobes Blue discoloration/pitting/scratches  → 
Replace the camshaft.
2. Measure:  Camshaft lobe dimensions “a” and “b” Out of specification  → Replace the cam-
shaft. 3. Measure:
 Camshaft runout Out of specification  → Replace.
4. Measure:  Camshaft-journal-to-camshaft-cap clear- ance
Out of specification  → Measure the cam-
shaft journal diameter.
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a. Install the camshaft...

CAMSHAFTS
5-12
NOTE:
 Tighten the camshaft cap bolts in stages and in a crisscross pattern, working from the 
inner caps out.
 Do not turn the camshaft when measuring  the camshaft journal-to-camshaft cap clear-
ance with the Plastigauge®.
d. Remove the camshaft caps and then mea- sure the width of the Plastigauge® “2”.
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5. Measure: Camshaft journal diameter “a” Out of specification  → Replace the cam-
shaft.
Within specification  → Replace the cylinder 
head and the...

CAMSHAFTS
5-13
Damage/wear → Replace the defective 
part(s).
EAS23970
CHECKING THE TIMING CHAIN TEN-
SIONER
1. Check:  Timing chain tensioner
Cracks/damage  → Replace.
2. Check:  One-way cam
Rough movement  → Replace the timing 
chain tensioner assembly.
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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....

CAMSHAFTS
5-14
3. Install: Dowel pins
 Intake camshaft caps
 Exhaust camshaft caps
NOTE:
 Make sure each camshaft cap is installed in its original place. Refer to the identification 
marks as follows:
“I1”, “I2”: Intake side camshaft cap mark
“E1”, “E2”: Exhaust side camshaft cap mark
 Make sure the arrow mark “a” on each cam- shaft points towards the right side of the 
engine.
4. Install:  Camshaft cap bolts
NOTE:
Tighten the camshaft cap bolts in stages and 
in a crisscross pattern,  working...

CAMSHAFTS
5-15
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7. Turn: Crankshaft
(several full turns clockwise)
8. Check: “T” mark “a”
Make sure the “T” mark on the pickup rotor 
is aligned with the crankcase mating sure 
face “b”.
 Camshaft sprocket  match mark “c”
Make sure the match marks on the cam-
shaft sprockets are aligned with the edge of 
the cylinder head “d”.
Out of alignment  → Adjust.
Refer to the installation steps above.
9. Tighten:
 Camshaft sprocket bolts “1”
CAUTION:
ECA4S81017
Be sure to...

CYLINDER HEAD
5-16
EAS24100
CYLINDER HEAD
Removing the cylinder head
Order Job/Parts to remove Q’ty RemarksIntake camshaft Refer to CAMSHAFTS on page 5-8.
Exhaust camshaft Refer to CAMSHAFTS on page 5-8.
1 Cylinder head 1
2 Cylinder head gasket 1
3Dowel pin 2 For installation, reverse the removal proce-
dure. 

CYLINDER HEAD
5-17
EAS24120
REMOVING THE CYLINDER HEAD
1. Remove: Cylinder head bolts
NOTE:
 Loosen the bolts in the proper sequence as 
shown.
 Loosen each bolts 1/2 of a turn at a time.  After all of the bolts are fully loosened, 
remove them.
EAS24160
CHECKING THE CYLINDER HEAD
1. Eliminate:
 Combustion chamber carbon deposits (with a rounded scraper)
NOTE:
Do not use a sharp instrument to avoid damag-
ing or scratching:
 Spark plug bore threads
Valve seats
2. Check: Cylinder head...

CYLINDER HEAD
5-18
NOTE:
Pass the timing chain through the timing chain 
cavity.
3. Tighten: Cylinder head bolts “1” – “10”
 Cylinder head bolts “11” “12”
NOTE:
 Lubricate the cylinder head bolts with engine 
oil.
 Tighten the cylinder head bolts in the proper  tightening sequence as shown and torque 
them in two stages.
 First, tighten the bolts “1” – “10” to approxi- mately 19 Nm (1.9 m·kg, 14 ft·lb) with a 
torque wrench and then tighten the 50 Nm 
(5.0 m·kg, 36 ft·lb).
4. Install:  Exhaust...

VALVES AND VALVE SPRINGS
5-19
EAS24270
VALVES AND VALVE SPRINGS
Removing the valves and valve springs
Order Job/Parts to remove Q’ty RemarksCylinder head Refer to CYLINDER HEAD on page 5-16.
1 Intake valve lifter 8
2 Intake valve pad 8
3 Intake valve cotter 16
4 Intake valve upper spring seat 8
5 Intake valve spring outer 8
6 Intake valve spring inner 8
7 Intake valve stem seal 8
8 Intake valve lower spring seat 8
9 Intake valve 8
10 Intake valve guide 8
11 Exhaust valve lifter 8
12 Exhaust valve pad 8...