MAINTENANCE SPECIFICATIONS

SPEC

 

 

 

 

 

Item

 

 

 

 

 

 

 

Standard

Limit

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Stem runout limit

----

0.01 mm

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

(0.0004 in)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Valve seat width

IN

0.9 ~ 1.1 mm

1.6 mm

 

 

(0.0354 ~ 0.0433 in)

(0.0630 in)

 

EX

0.9 ~ 1.1 mm

1.6 mm

 

 

(0.0354 ~ 0.0433 in)

(0.0630 in)

 

 

 

 

Valve spring:

 

 

 

Free length

IN

37.81 mm (1.49 in)

35.9 mm

 

 

 

(1.41 in)

 

EX

37.54 mm (1.48 in)

35.7 mm

 

 

 

(1.41 in)

Set length (valve closed)

IN

29.13 mm (1.15 in)

----

 

EX

29.30 mm (1.15 in)

----

Compressed force (installed)

IN

99 ~ 114 N at 29.13 mm

----

 

 

(9.9 ~ 11.4 kg at 29.13 mm,

 

 

 

22.27 ~ 25.57 lb at 1.15 in)

 

 

EX

126 ~ 144 N at 29.30 mm

----

 

 

(12.6 ~ 14.4 kg at 29.30 mm,

 

 

 

28.44 ~ 32.41 lb at 1.15 in)

 

Tilt limit *

IN

----

2.5°/ 1.7 mm

 

 

 

(2.5°/0.067 in)

 

EX

----

2.5°/1.6 mm

 

 

 

(2.5°/0.063 in)

Direction of winding (top view)

IN

Clockwise

----

 

 

 

 

 

EX

Clockwise

----

 

 

 

 

 

 

 

 

 

Piston:

 

 

 

 

Piston to cylinder clearance

 

 

0.040 ~ 0.065 mm

0.1 mm

 

 

 

 

 

 

 

(0.0016 ~ 0.0026 in)

(0.004 in)

Piston size “D”

 

 

76.955 ~ 76.970 mm

----

 

 

 

 

 

 

 

(3.0297 ~ 3.0303 in)

 

 

 

 

 

 

H

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

D

 

 

 

 

 

 

 

 

 

 

Measuring point “H”

 

 

8 mm (0.31 in)

----

Piston off-set

 

 

0.5 mm (0.020 in)/IN-side

----

2 - 6

Page 43
Image 43
Yamaha WR250FM service manual 1.6 mm