Yanmar 3JH4BE - Valve Springs

5. Inspection and Servicing of Basic Engine Parts
101
5.2.4 Valve springs
(1) Checking valve springs
1) Check the spring for scratches or corrosion.
2) Measure the free length of the spring.
3) Measure inclination.
4) Measure spring tension.
5) Assembling valve springs.
The side with the smaller pitch (painted yellow)
should face down (cylinder head).
NOTE:
The pitch of the valve spring is not even. The side with the smaller pitch (yellow) should face down
(cylinder head) when assembled.
Valve spring Unit Standard Limit
Free length A mm 44.4 43.0
Inclination B mm – 1.1
Tension
(1mm pressure)
(Smaller pitch/
Larger pitch)
N/mm
(kgf/mm)
26.6/35.4
(2.71/3.61)
–
Free length
(Valve spring)
Inclination
(Valve spring)
B
A
Square gauge
Spring tension teste
r
Up side
Smaller pitch side (yellow)
Down side