Yamaha Fz1n Service Manual

VALVES AND VALVE SPRINGS
5-23
16 Exhaust valve lower spring seat 8
17 Exhaust valve 8
18 Exhaust valve guide 8For installation, reverse the removal 
procedure.
Removing the valves and valve springs
Order Job/Parts to remove Q’ty Remarks 

VALVES AND VALVE SPRINGS
5-24
EAS24280
REMOVING THE VALVES
The following procedure applies to all of the 
valves and related components.
NOTE:
Before removing the internal parts of the cylin-
der head (e.g., valves, valve springs, valve 
seats), make sure the valves properly seal.
1. Remove: Valve lifter “1”
 Valve pad “2”
NOTE:
Make a note of the position of each valve lifter 
and valve pad so that they can be reinstalled in 
their original place.
2. Check:
 Valve sealingLeakage at the valve seat  →...

VALVES AND VALVE SPRINGS
5-25
EAS24290
CHECKING THE VALVES AND VALVE 
GUIDES
The following procedure applies to all of the 
valves and valve guides.
1. Measure: Valve-stem-to-valve-guide clearance
Out of specification  → Replace the valve 
guide.
2. Replace: Valve guideNOTE:
To ease valve guide removal and installation, 
and to maintain the corre ct fit, heat the cylinder 
head to 100°C (212 °F) in an oven.
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
a. Remove the valve guide with the valve 
guide remover “1”.
b....

VALVES AND VALVE SPRINGS
5-26
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
3. Eliminate: Carbon deposits(from the valve face and valve seat)
4. Check:
Valve facePitting/wear  → Grind the valve face.
 Valve stem end
Mushroom shape or diameter larger than 
the body of the valve stem  → Replace the 
valve.
5. Measure:  Valve margin thickness “a”Out of specification  → Replace the valve. 6. Measure:
 Valve stem runoutOut of specification  → Replace the valve.
NOTE:
 When installing a new valve, always replace 
the...

VALVES AND VALVE SPRINGS
5-27
▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼▼
a. Apply Mechanic’s blueing dye (Dykem) “b” onto the valve face.
b. Install the valve into the cylinder head.
c. Press the valve through the valve guide  and onto the valve seat to make a clear 
impression.
d. Measure the valve seat width.
NOTE:
Where the valve seat and valve face contacted 
one another, the blueing will have been 
removed.
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
4. Lap: Valve face
 Valve seat
NOTE:
After replacing the cylinder head...

VALVES AND VALVE SPRINGS
5-28
h. Install the valve into the cylinder head.
i. Press the valve through the valve guide and onto the valve seat to make a clear 
impression.
j. Measure the valve seat width “c” again. If  the valve seat width is out of specification, 
reface and lap the valve seat.
▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲▲
EAS24310
CHECKING THE VALVE SPRINGS
The following procedure applies to all of the 
valve springs.
1. Measure: Valve spring free length “a”
Out of specification  → Replace the valve...

VALVES AND VALVE SPRINGS
5-29
EAS24320
CHECKING THE VALVE LIFTERS
The following procedure applies to all of the 
valve lifters.
1. Check: Valve lifterDamage/scratches  → Replace the valve 
lifters and cylinder head.
EAS24330
INSTALLING THE VALVES
The following procedure applies to all of the 
valves and related components.
1. Deburr:  Valve stem end(with an oil stone)
2. Lubricate:  Valve stem “1”
 Valve stem seal “2”(with the recommended lubricant) 3. Install:
Valve “1”
 Lower spring seat “2”
...

VALVES AND VALVE SPRINGS
5-30
5. To secure the valve cotters onto the valve stem, lightly tap the valve tip with a soft-
face hammer.
CAUTION:
ECA13800
Hitting the valve tip with excessive force 
could damage the valve.
6. Install:
 Valve pad “1”
 Valve lifter “2”
NOTE:
 Lubricate the valve lifter and valve pad with molybdenum disulfide oil.
 The valve lifter must move smoothly when  rotated with a finger.  Each valve lifter and valve pad must be rein-
stalled in its original position.Valve spring...

GENERATOR
5-31
EAS24480
GENERATOR
Removing the generator
Order Job/Parts to remove Q’ty RemarksRider and passenger seat Refer to GENERAL CHASSIS on  page 4-1.
Fuel tank Refer to FUEL TANK on page 7-1.
Engine oil Drain. Refer to CHANGING THE ENGINE 
OIL on page 3-12.
1 Stator coil assembly  lead coupler 1 Disconnect.
2Plug 1
3 Generator rotor cover 1
4Gasket 1
5 Dowel pin 2
6 Generator rotor assembly 1
7 Stator coil assembly 1
8 Dowel pin 2
9 Bearing housing 1
10 Collar 1 

GENERATOR
5-32
11 Bearing 1
12 Stator coil assembly lead holder 1
13 Idler gear 1
14 Idler gear shaft 1
15 Washer 1
16 Bearing 1For assembly, reverse the removal 
procedure.
Removing the generator
Order Job/Parts to remove Q’ty Remarks