Yamaha SXV70SJ Supplementary Service Manual - Eng

5-10

ENG

CYLINDER HEAD AND CYLINDER

SCH5160

SCH5170

SCH5180

7. Eliminate:

•

Score marks and lacquer deposits

(from the piston wall)

Use 600 ~ 800 grit wet sandpaper.

NOTE:

Sand in a crisscross pattern. Do not sand exces-

sively.

8. Measure:

•

Piston-to-cylinder clearance

Measurement steps:

1st step:

•

Measure the cylinder bore (C) with a cylinder bore

gauge 

1

.

NOTE:

Measure the cylinder bore (C) parallel to and at right

angles to the crankshaft. Then find the average of the

measurements.

C = Maximum D

T = (Maximum of D

1

 or D

2

) –

(Maximum of D

5

 or D

6

)

R = (Maximum of D

1

, D

3

 or D

5

) –

(Minimum of D

2

, D

4

 or D

6

)

•

If out of specification, replace cylinder, and re-

place piston and piston rings as a set.

Standard

Wear limit

Cylinder bore

(C)

Taper (T)

Out of round

(R)

70.600 mm

(2.7795 in)

0.05 mm

(0.002 in)

0.01 mm

(0.0004 in)

70.500 ~ 70.520 mm

(2.7756 ~ 2.7764  in)

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