Valve Springs - Yanmar 3YM30 Service Manual

4) Valve stem seals
The valve stem seals in the intake/exhaust valve
guides cannot be re-used. When they are
removed, be sure to replace them.
When assembling the intake/exhaust valves,
apply an adequate quantity of engine oil on the
valve stem before inserting them.
Exhaust stem seal is marked by yellow. Intake
stem seal is not marked.
a) Apply lube oil to the lip.
b) Push with the inserting tool for installation.
Measure and check the projection of valve stem seal to
keep proper clearance between valve guide and stem
seal.
Valve stem seal projection (mm)
10.9-11.2

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.
Square gauge
5. Inspection and servicing of basic engine parts
B
A
112R1
Valve stem seal inserting tool
Stem seal
Valve guide
Cylinder head
(Stem seal insertion)
Free length
(Valve spring)
001509-00E
Inclination
(Valve spring)
001511-00E