Valve Stem Seal Replacement - Yanmar 3TNV Series Service Manual

4. Disassembly, Inspection and Reassembly of Engines

4.2.8 Valve stem seal replacement

Always use a new seal after the intake/exhaust valve
is disassembled. Since the one for the exhaust valve
is marked with yellow paint, do not confuse the intake
and exhaust valves.
1) Apply engine oil to the lip.
2) Push with the inserting tool (Refer to No.5 of
4.1.2 in Chapter 4) for installation.
3) Measure and check the projection of valve stem
seal to keep proper clearance between valve
guide and stem seal.
Model Number of valves
3TNV82A
4TNV84
3TNV84(T)
4TNV88
4TNV84T
4TNV94L
4TNV98(T)
4TNE106(T)
Projection
15.7 16.0
2 valves
18.7 19.0
9.9 10.2
4 valves 11.7 12.0
15.4 15.6
mm
82