Yanmar 6LY3 series Service Manual page 99

Inspecting the Cylinder Block and Components
12/05
3. Measure the valve spring inclination
(Figure 5-29, (1)).
Valve Spring Inclination Limit
1.2 mm (0.047 in.)
Figure 5-29
Figure 5-29
1 – Valve Spring Inclination
2 – Valve Spring Free Length
4. Measure the valve spring free length
(Figure 5-29, (2)) and tension.
Valve Spring
Free Length
K1 = 17.5 N / mm
Tension at
(62.9 ozf / 0.399 in.)
1 mm (0.039 in.)
K2 = 22.9 N / mm
Compression
(82.3 ozf / 0.399 in.)
6LY3 Service Manual
(1)
(2)
0005663
0005610
Standard Limit
53.0 mm 51.5 mm
(2.086 in.) (2.027 in.)
(1.78 kgf / mm) —
(2.33 kgf / mm) —
© 2007 Yanmar Marine International
Figure 5-30
Figure 5-30
1 – Spring Tension Tester
5. Assemble the valve springs. The side with the
smaller pitch (painted yellow) (Figure 5-31, (2))
should face down toward the cylinder head.
NOTICE: The pitch of this valve spring is not
even. Pay attention to the up-down direction of
the spring when assembling.
Figure 5-31
(1)
(3)
Figure 5-31
1 – Top
2 – Small Pitch Side (Yellow)
3 – Down Side
ENGINE
(1)
0005611
(2)
0005612
5-33