Takeuchi TB108 Werkstatt-Handbuch Seite 300

4. Disassembly, inspection and reassembly of engines
4.2.7 Valve guide replacement
1)Use a valve guide extraction tool(4.1.2(1) No.1 in
Chapter 4) and extract the valve guide from the cyl-
inder head.
2)Put liquid nitrogen or ether (or alcohol) with dry ice
added in a container and put the valve guide for
replacement in it for cooling. Then insert it in with a
valve guide inserting tool (Refer to No.2 of 4.1.2(1) in
Chapter 4).
Do not touch the cooled valve guide with bare hands
to avoid skin damage.
3)Check the inside diameter and finish to the standard
inside diameter as required with a reamer.
4)Check the projection from the cylinder head.
Projection
9.8 to 10.0
4.2.8 Valve stem seal replacement
Always use a new valve stem seal after the intake/
exhaust valve or valve stem seal is disassembled. Since
the one for the exhaust valve is marked with yellow
paint, do not confuse the intake and exhaust valves.
[NOTICE]
Painting is applied to the springs of both intake/
exhaust valve stem seals for the distinction because
both parts are different. Be careful because it causes
oil down when the attachment of intake/ exhaust is
mistaken.
Distinction coloration for the intake is "white" and for
the exhaust "black".
1)Apply lube oil to the lip.
2)Push with the inserting tool (Refer to No.5 of 4.1.2(1)
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.
Projection
10.9 to 11.2
(mm)
(mm)
Cylinder head
Valve guide replacement
Valve stem seal inserting tool
Stem seal insertion
Valve guide projection
Stem seal projection
67
Valve guide extracting
& inserting tool
Projection
Valve guide
Stem seal
Valve guide
Cylinder head
Stem seal
Valve guide