Yamaha FZR400 Service Manual Ch4
ENGINE REMOVAL
ENGINE OVERHAUL
ENGINE REMOVAL
NOTE:
It is not necessary to remove the engine in order
to remove the following components:
??
Cylinder head
?? Cylinder
0
Piston
. Clutch
0
Water pump
?? A.C. magneto
LOWER COWLING, CENTER COWLING,
UPPER COWLING AND TOP COVER
1. Remove:
?? Lower cowlings (Left and right)
?? Center cowlings (Left and right)
0
Upper cowling
0 Seat
??
Top cover
Refer to the “COWLING REMOVAL
AND INSTALLATION - REMOVAL”
section in the CHAPTER 3.
FUEL TANK
1. Remove:
?? Fuel tank
Refer to the “CARBURETOR - REMOVAL” section in the CHAPTER 6.
ENGINE OIL
1. Drain:
??
Engine oil
Refer to the “ENGINE OIL REPLACE-
MENT” section in the CHAPTER 3.
COOLANT
1. Drain:
0
Coolant
Refer to the “COOLANT REPLACE-
MENT” section in the CHAPTER 3.
AIR FILTER CASE AND CARBURETOR
1. Remove:
??
Air filter case
??
Carburetor
Refer to the “CARBURETOR - RE-
MOVAL” section in the CHAPTER 6.
4-1
ENGINE REMOVAL
RADIATOR
1. Disconnect:
?? Hose (Radiator
?? Hose (Radiator
2. Disconnect:
?? Fan motor coupler
3. Remove:
??
Radiator assembly
Cover the cylinder head cover and the fender
with rugs to prevent a scratching.
-
Inlet)
-
Outlet)
@
@
4. Disconnect:
?? Pipes (Left and right)
5. Remove:
?? Pipes (Radiator
-
MUFFLER ASSEMBLY
1. Remove:
?? Nuts (Exhaust pipe)
?? Cowling stays
?? Bolt (Muffler bracket)
@
Outlet)
@
@
@
4-2
ENGINE DISASSEMBLY
MUFFLER ASSEMBLY (For California only)
1. Remove:
?? Nuts (Exhaust pipe)
??
Cowling stays
?? Bolt (Muffler bracket)
2. Remove:
??
Bolt (Muffler stay)
@
@
@
3. Loosen:
?? Lock nut
?? Adjuster
4. Remove:
0
Cover
??
Clips
aPulley @
*Cables @
5. Remove:
*Washer @
??
Bracket
?? Housing
??
Gasket
(Left side)
??
Shaft arm
@
@
0
@
@
4-3
ENGINE REMOVAL
CLUTCH CABLE AND DRIVE CHAIN
1. Remove:
?? Shift arm
?? Crankcase cover (Left)
2. Remove:
?? Clutch cable
3. Straighten:
?? Lock washer tab
4. Remove:
?? Drive sprocket
LEADS
1. Straighten:
0
Clamp
2. Disconnect:
?? Battery leads
NOTE:
Disconnect the negative lead @ first.
ENGINE REMOVAL
3. Disconnect:
?? Lead (Starter motor)
4. Remove:
0
Cover
5. Disconnect:
?? Coupler (Oil level Neutral switch)
?? Coupler (A.C. generator)
?? Coupler (Sidestand switch)
6. Remove:
??
Spark plug leads
ENGINE REMOVAL
1. Remove:
@Cover @
aStarter
lever
0
2. Place a suitable stand under the engine.
3. Remove:
i
I
?? Down tube frames (Left and right)
?? Bolt (Engine-mount)
@
@
ENGINE REMOVAL
4. Remove:
?? Bolt (Engine-mounting Lower)
?? Bolt (Engine-mounting Upper)
??
Collars
@
@
@
5. Remove:
??
Engine assembly.
From right side.
4-6
ENGINE DISASSEMBLY
ENGINE DISASSEMBLY
CYLINDER HEAD COVER, CAMSHAFT AND
CYLINDER HEAD
NOTE:
With the engine mounted, the cylinder head
cover,
maintained by removing the following parts.
?? Lower cowlings (Left and right)
?? Center cowlings (Left and right)
??
??
??
@Air
??
??
?? Down tube frame (Right)
camshaft and cylinder head can be
Seat
Top cover
Radiator
filter case
Carburetor
Muffler assembly
1. Remove:
@Cylinder head cover
??
Gasket (Cylinder head cover)
*Spark plugs
@
2. Remove:
@Generator cover
??
Dowel pins
3. Turn:
??
Crankshaft
Counterclockwise
4. Align:
?? “T” mark
??
Crankcase end
@
@
@
@
NOTE:
When #1 piston is at TDC on compression
stroke.
ENGINE DISASSEMBLY
5. Remove:
??
Cam chain tensioner
?? Gasket (Cam chain tensioner)
6. Remove:
?? Union bolts
?? Oil delivery pipe
@
@
@
7. Remove:
??
Cam chain guide (Upper)
??
Cam chain guide (Exhaust side)
@
@
NOTE:
?? Select either of the two procedures explained
in this manual, as follows:
??
Procedure 1.
For engine service except cylinder head dis-
assembly.
-+
Disconnect the cam chain.
The pistons and cylinder can be removed
without removing the camshafts.
??
Procedure 2.
For engine service including cylinder head
disassembly.
--f
Remove the cam caps and camshafts.
The camshafts can be removed without disconnecting the cam chain.
4-8
ENGINE DISASSEMBLY
)
ENG
lq-1
Procedure
1.
Disconnect:
??
2. Remove:
?? Rubbers (Camshaft cap)
3. Remove:
?? Nuts (Cylinder head)
4. Remove:
?? Cylinder head
?? Gasket (Cylinder head)
o
Dowel pins
5. Go to “CYLINDER AND PISTON”.
1.
Cam chain
Use the Cam Chain Cutter @ .
Cam Chain Cutter:
P/N YM-01112
@
Use the Hexagon Wrench 6 mm (0.24
in)@.
Procedure 2.
1. Remove:
??
Camshaft caps
??
Dowel pins
NOTE:
Remove the camshaft caps in a crisscross pattern
from outermost to inner caps.
A
CAUTIOM:
Do not rotate the camshaft or valve damage may
occur.
2. Remove:
??
Camshafts
Fasten safety wire @ to the cam chain to pre-
vent it from falling into the crankcase.
4-9
ENGINE DISASSEMBLY
3. Remove:
?? Nuts (Cylinder head)
Use the Hexagon Wrench 6 mm (0.24 in)@.
NOTE:
?? Loosen the nuts in their proper loosening
sequence.
?? Follow numerical order shown in photo.
Start by loosening each nut
all are loose.
4. Remove:
??
Cylinder head
NOTE:
Remove the cylinder head as a whole to prevent
the valve lifters and adjusting pads from falling
into the crankcase.
l/2
turn until
5. Remove:
aGasket
@Dowel
(Cylinder head)
pins
@
@
CYLINDER AND PISTON
NOTE:
With the engine mounted, the cylinder and piston
can be maintained by removing the following
parts.
?? Lower cowlings (Left and right)
??
Center cowlings (Left and right)
??
Seat
*Top
cover
??
Radiator
??
Air filter case
??
Carburetor
??
Muffler assembly
?? Down tube frame (Right)
??
Cylinder head
4-10
ENGINE DISASSEMBLY
1. Remove:
0
Water pipe
0
O-rings
?? Cylinder
2. Remove:
?? Gasket (Cylinder)
?? Dowel pins
3. Mark:
0 Pistons
With the piston number designations as
shown.
@
@
@
4. Remove:
??
Circlips (Piston pin)
@
NOTE:
Before removing the piston pin circlip, cover the
crankcase with a clean rag to prevent the circlip
from falling into the crankcase cavity.
5. Remove:
??
Piston pins
0
Pistons
0
@
NOTE:
Before removing the piston pin, deburr the clip
grooved and pin hole area. If the piston pin
groove is deburred and piston pin is still difficult
to remove, use the Piston Pin Puller
0.
Piston Pin Puller:
P/N YU-01304
Do not use a hammer to drive the piston pin
out.
4-11
ENGINE DISASSEMBLY
STARTER CLUTCH
NOTE:
With the engine mounted, the starter clutch can
be maintained by removing the following parts.
?? Lower cowling (Right)
?? Starter clutch cover
1. Remove:
*Starter
?? Gasket (Starter clutch cover)
??
clutch cover
Dowel pens.
@
2. Remove:
?? Bolt (Starter clutch)
??
Washer
3. Attach:
?? Heavy Duty Puller
Heavy Duty Puller:
Y U-33270
4. Remove:
?? Starter clutch
5. Remove:
?? woodruff key
??
Starter clutch gear
?? Idle gear
?? Idle gear
@I
@
@
@
@
@
@
4-12
ENGINE DISASSEMBLY
CLUTCH
NOTE:
With the engine mounted, the starter clutch can
be maintained by removing the following parts.
?? Lower cowling (Right)
??
Crankcase cover (Right)
1. Remove:
?? Crankcase cover (Right)
??
Gasket (Crankcase cover)
??
Dowel pins
NOTE:
Working in a crisscross pattern, loosen bolts
turn each. Remove them after all are loosened.
@
l/4
2.
Remove:
?? Bolts (Clutch spring)
*Clutch springs
??
Pressure plate
??
Friction plates
??
Clutch plates
@
@
@
NOTE:
Loosen the bolts in a crisscross pattern.
3. Remove:
?? Push rod
#l @
aBall @
?? Push rod
#2 @
4. Straighten the lock washer tabs.
5. Loosen:
@Nut
(Clutch boss)
Use the Universal Clutch Holder
@
0.
Universal Clutch Holder:
P/N Y M-91 042
NOTE:
Hold the clutch boss loosen the nut by Universal
Clutch Holder
0.
ENGINE DISASSEMBLY
6. Remove:
.Nut
(Clutch boss)
??
Lock washer
@Clutch
thrust
boss
washer
7. Remove:
??
Spacer
@
??
Bearing
@
NOTE:
Install the 5 mm (0.2 in) screw @ on the spacer
@
then remove the spacer with pulling out
screw.
@
@
@
@
8.
Remove:
aClutch
housing
9. Remove:
??
Thrust washer
*Collar
@
A.C. MAGNETO
@
@
NOTE:
With the engine mounted, the A.C. Magneto can
be maintained by removing the following parts.
?? Lower cowling ( Left)
??
Generator cover
4-14
ENGINE DISASSEMBLY
1. Remove:
@Bolt
(Magneto)
??
Washer
NOTE:
Hold the magneto to loosen the nut by the
Universal Rotor Holder
Universal Rotor Holder:
LFI
2. Attach:
0
3.
*Magneto @
P/N YU-01235
Rotor puller
P/N YM-01080
Remove:
@
0.
@
I
4. Remove:
??
Starter coil assembly
??
Pickup coil
@Woodruff
WATER PUMP
NOTE:
With the engine mounted, the water pump can
be maintained by removing the following parts.
0 Seat
??
Top cover
?? Lower cowling
aShift
arm
??
Crankcase cover (Right)
0 Water pipe
0
Water pump cover
@
key
(
Right)
@
@
4-15
ENGINE DISASSEMBLY
OIL PUMP AND SHIFT SHAFT
NOTE:
With the engine mounted, the oil pump and
shift shaft can be maintained by removing the
following parts.
?? Lower cowling (Right)
??
Crankcase cover (Right)
??
Clutch housing
1. Remove:
*Oil
pump assembly
2. Remove:
*Gasket
??
Dowel pin
(Oil pump assembly)
@
@
@
4-16
ENGINE DISASSEMBLY
(ENG lb1
3. Remove:
??
Shift shaft assembly
@
OIL PAN AND OIL STRAINER
NOTE:
With the engine mounted, the oil pan and oil
strainer can be maintained by removing the
following parts.
?? Lower cowlings (Left and right)
?? Muffler assembly
scowling
stay
1. Disconnect:
?? 0il level switch lead
?? Neutral switch lead
2. Remove:
0
Oil filter cover
??
Oil filter
3. Remove:
@Drain
plug
@
?? 0il level switch
??
Oil pan
@
??
Gasket (Oil pan)
??
Dowel pins
@
@
@
@
4-17
ENGINE DISASSEMBLY
4. Remove:
0
Oil strainer cover
?? Relief valve
5. Remove:
??
Oil strainer assembly
0
@
@
STARTER MOTOR
NOTE:
With the engine mounted, the starter motor,
can be maintained by removing the following
parts.
0
Seat
??
Top cover
??
Fuel tank
1. Remove:
??
Starter motor
??
crankcase ventilation hose
CRANKCASE
0
@
DlSASSErVlBLY
1. Remove:
0
Oil seal stopper
@
4-18
ENGINE DISASSEMBLY
A
J
3. Remove:
??
Bolts (Crankcase)
NOTE:
G
?? Remove the bolts starting with the highest
numbered one.
*The
embossed numbers in the crankcase
designate the crankcase tightening sequence.
4. Place the engine upside down.
5. Remove:
?? Crankcase (Lower)
Use a soft hammer.
??
Upper case
ower case
[BIL
TRANSMISSION, SHIFTER AND SHIFT CAM
1. Remove:
??
Transmission assembly
??
Dowel pins
@
2. Remove:
@Stopper
lever
0
?? Stopper plate (Shift cam)
3. Remove:
?? Guide bars
@Shift
fork #l
*Shift
fork #2
aShift
fork #3
@
@
@
@
@
ENGINE DISASSEMBLY
4. Remove:
??
Shift cam
CRANKSHAFT
1. Remove:
??
Crankshaft assembly
2. Remove:
??
Main journal bearing
NOTE:
Identify each main journal bearing position
very carefully so that it can be reinstalled in
its original place.
4. Remove:
??
Neutral switch
4-20
ENGINE DISASSEMBLY
5. Remove:
??
Breather hose
@Oil
baffle plate
VALVE PAD AND VALVE
NOTE:
With the engine mounted, the valve pad and
valve can be maintained by removing the
following parts.
?? Lower cowlings (Left and right)
@Center cowlings (Left and right)
??
Fuel tank
??
Carburetor
??
Radiator
@Generator cover
?? Cylinder head cover
eCam
chain tensioner
@Cylinder head
1. Remove:
0
Lifters
??
Valve pads
0
NOTE:
Identify each lifter and pad position very
fuly so that it can be reinstalled in its original
4-21
place.
@ Lifters
@
Valve pads
--
care-
ENGINE DISASSEMBLY
2. Check:
0
Valve sealing
Leakage at valve seat + inspect the valve
face, valve seat and valve seat width.
Refer to the “INSPECTION AND REPAIR
-
VALVE SEAT” section.
NOTE:
Before removing the internal parts (valve, valve
spring, spring seat, etc.) of the cylinder head, the
valve sealing should be checked.
Valve seal checking steps:
?? Supply a clean solvent
and exhaust ports.
?? Check the valve sealing. There should be no
leakage at the valve seats
@
into the intake
0.
3. Attach:
0
Valve spring compressor
?? Attachment
@
@
Valve Spring Compressor:
P/N YM-04019
Attachment:
P/N Y M-04108
@Valve
retainers
4. Remove:
0
Valve retainers
0
Valve spring seat
*Oil
seal
@I
0
Valve spring
@
@
@
*Valve @
*Valve
spring seat
@
NOTE:
Identify each part position very
carefuly
it can be reinstalled in its original place.
so that
ENGINE DISASSEMBLY
CONNECTING ROD
1. Remove:
??
connecting rod
?? Connecting rod bearing
INNER ROTOR (OIL PUMP)
1. Remove:
??
Pump housing
@
2. Remove:
*Outer
rotor
@Pin @
0
Inner rotor
??
Washer
0
Pump cover
?? Pump shaft
@
0
@
@
@
4-23
INSPECTION AND REPAIR
INSPECTION AND REPAIR
CYLINDER HEAD
1. Eliminate:
??
NOTE:
Do not use a sharp instrument and avoid
--
ing or scratching:
??
??
Va Ive seat
2. Inspect:
??
Carbon deposit
(from combustion chamber)
Use rounded scraper.
damag-
Spark plug threads
Cylinder head
Scratches/Damage + Replace.
3. Measure:
0 Warpage
Out of specification -+ Resurface.
Cylinder Head Warpage:
Less than 0.03 mm (0.0012 in)
4. Resurface:
??
Cylinder head
Resurfacement steps:
Place a 400
600 grit wet sandpaper on the
-
surface plate, and resurface the head using a
figure-eight sanding pattern.
NOTE:
Rotate the head several times to avoid remov-
ing too much material from one side.
I
I
4-24
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