1999 YAMAHA YZF-R7 remove seats

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ENGCYLINDER HEAD
EB402102
REMOVING THE CYLINDER HEAD
1. Remove:
• cylinder head bolts
• cylinder head nuts
NOTE:
• Loosen each bolt and nut 1/2 of a turn
at a time, in stages and in a crisscross
pattern. After all of the bolts and nuts
are fully loosened, remove them.
• Loosen the bolts and nuts in decreas-
ing numerical order (refer to the num-
bers in the illustration).
EB402402
CHECKING THE CYLINDER HEAD
1. Eliminate:
• combustion chamber carbon deposits
(with a rounded scraper)
NOTE:
Do not use a sharp instrument to avoid
damaging or scratching:
• spark plug bore threads
• valve seats
2. Check:
• cylinder head
Damage/scratches ® Replace.
• cylinder head water jacket
Mineral deposits/rust ® Eliminate.

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ENGVALVES AND VALVE SPRINGS
EB403100
REMOVING THE VALVES
The following procedure applies to all of
the valves and related components.
NOTE:
Before removing the internal parts of the
cylinder head (e.g., valves, valve
springs, valve seats), make sure that 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
(for leakage)
Leakage at the valve seat ® Check the
valve face, valve seat, and valve seat
width.
Refer to “CHECKING THE VALVE
SEATS”.
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a. Pour a clean solvent a into the intake
and exhaust ports.
b. Check that the valves properly seal.
NOTE:
There should be no leakage at the valve
seat 1.
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ENGVALVES AND VALVE SPRINGS
5. Measure:
• valve margin thickness a
Out of specification ® Replace the
valve.
6. Measure:
• valve stem runout
Out of specification ® Replace the
valve.
NOTE:
• When installing a new valve, always
replace the valve guide.
• If the valve is removed or replaced,
always replace the oil seal.
Valve margin thickness
Intake
0.9 ~ 1.2 mm
(0.028 ~ 0.047 in)
Exhaust
1.0 ~ 1.3 mm
(0.039 ~ 0.051 in)
Valve stem runout
0.01 mm (0.0004 in)
EB403410
CHECKING THE VALVE SEATS
The following procedure applies to all of
the valves and valve seats.
1. Eliminate:
• carbon deposits
(from the valve face and valve seat)
2. Check:
• valve seat
Pitting/wear ® Replace the cylinder
head.
3. Measure:
• valve seat width a
Out of specification ® Replace the cyl-
inder head.
Valve seat width
0.9 ~ 1.1 mm
(0.035 ~ 0.043 in)
: 1.6 mm (0.06 in)

4 - 69
ENGCONNECTING RODS AND PISTONS
c. Put a piece of Plastigaugeâ 1 on the
crankshaft pin.
d. Assemble the connecting rod halves.
NOTE:
• Do not move the connecting rod or
crankshaft until the clearance mea-
surement has been completed.
• Lubricate the bolt threads and nut
seats with MOLYKOTE
® G-n paste.
• Make sure that the “Y” mark c on the
connecting rod faces towards the left
side of the crankshaft.
• Make sure that the characters d on
both the connecting rod and connect-
ing rod cap are aligned.
e. Tighten the connecting rod nuts.
Refer to “INSTALLING THE PISTONS
AND CONNECTING RODS”.
f. Remove the connecting rod and big
end bearings.
Refer to “REMOVING THE CONNECT-
ING RODS AND PISTONS”.
g. Measure the compressed Plasti-
gauge
â width e on the crankshaft
pin.
If the crankshaft pin-to-big end bear-
ing clearance is out of specification,
select replacement big end bearings.
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5 - 3
COOL

EB502000
RADIATOR AND THERMOSTAT
Order Job/Part Q’ty Remarks
Removing the thermostat assembly
Remove the parts in the order listed.
Rider seat and fuel tank Refer to “SEATS” and “FUEL TANK” in
chapter 3.
Air filter case and rubber cover Refer to “AIR FILTER CASE AND IGNI-
TION COIL PLATE” in chapter 3.
Carburetor assembly Refer to “CARBURETORS” in chapter 6.
Coolant Drain.
Refer to “CHANGING THE COOLANT”
in chapter 3.
Fuel tank and air filter case cover Refer to “FUEL TANK AND AIR FIL-
TER” in chapter 3.
Air filter case Refer to “ELECTRONIC FUEL INJEC-
TION” in chapter 6.
1 Thermostat assembly 1
2 Thermostat assembly inlet hose 1
RADIATOR AND THERMOSTAT