Yamaha F50D Servise Manual - page 180

Power unit

7-39

POWR

Installing the valve

1.

Install a new valve seal 

1

  to the valve

guide.

2.

Install the valve 

2

, valve spring seat 

3

,

valve spring 

4

, and spring retainer 

5

,

and then attach the special service tool

6

 and 

7

.

TIP:

Face the fine pitch side 

a

 of the valve spring

toward the spring seat.

3.

Compress the valve spring, and then

install the valve cotter 

8

.

4.

Lightly tap the spring retainer with a plas-

tic hammer to set the valve cotters

securely.

Cylinder head warpage limit:

0.10 mm (0.0039 in)

1

2

1

Valve spring compressor 

6

: 90890-04019

Valve spring compressor attachment 

7

:

90890-06320

a

2

3

4

5

7

6

8