Yamaha WR250F(N), Owner'S Service Manual

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4 - 40
ENG
VALVES AND VALVE SPRINGS
Combination of cylinder head and valve lifter
1. Combination:
For this combination, match the paint color
on the cylinder head with that on the valve
lifter according to the chart below.
NOTE:
When you purchase a cylinder head, you can-
not designate its size. Choose the valve lifter
that matches the above chart.
Combination
Cylinder head mark
a
(color)
Valve lifter mark
b
(color)
Red Red
Blue Blue
Yellow Yellow
Purple Black
a
b
ASSEMBLY AND INSTALLATION
Valve and valve spring
1. Apply:
●
Molybdenum disulfide oil
Onto the valve stem and valve stem
seal.
2. Install:
●
Valve 1
●
Valve spring seat 2
●
Valve stem seal 3
●
Valve spring 4
●
Valve spring retainer 5
To cylinder head.
NOTE:
●
Make sure that each valve is installed in its
original place, also referring to the painted
color as follows.
Intake (middle)
a
: yellow
Intake (right/left)
b
: white
Exhaust: no paint
●
Install the valve springs with the larger pitch
c
facing upward.
d
Smaller pitch