seats YAMAHA TTR90 2001 Owners Manual

4 - 20
ENG

VALVES AND VALVE SPRINGS
ASSEMBLY AND INSTALLATION
1. Apply:
l
Molybdenum disulfide oil
(onto the valve stem and valve stem
seal)
2. Install:
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Valve stem seats
l
Valves
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Valve springs
l
Valve spring retainers
NOTE:

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Make sure that each valve is installed in its
original place, also referring to the embossed
mark as follows.
Intake: “G”
Exhaust: “L”
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Install the valve springs with the larger pitch
a
facing upwards.
b
Smaller pitch
New

3. Install:
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Valve cotters
NOTE:

While compressing the valve spring with a
valve spring compressor and attachment
1
install the valve cotters.
Valve spring compressor:
YM-4019/90890-04019
4. To secure the valve cotters onto the
valve stem, lightly tap the valve tip with a
piece of wood.
CAUTION:

Hitting the valve tip with excessive force
could damage the valve.