2
Series 4137 Components - HT
This service manual contains
detailed descriptions of all typical
repair and servicing procedures for
models HT 70 and HT 75, which are
based on the series 4137
powerhead.
If there is no specific reference to
individual machines, the procedure
is the same for all machines. There
may be minor differences in the
illustrations, depending on the
machine, but the methods used and
the sequence of operations are
identical.
You will find detailed descriptions of
procedures for servicing and
repairing engine components and
CombiTools in the service manuals
for the “Series 4137 Powerhead“
and “CombiTools”.
You should make use of the
illustrated parts lists while carrying
out repair work. They show the
installed positions of the individual
components and assemblies.
Refer to the latest edition of the
relevant parts list to check the part
numbers of any replacement parts.
A fault on the machine may have
several causes. To help locate the
fault, consult the chapter on
"Troubleshooting" in this manual
and the "STIHL Service Training
System" for all assemblies.
Refer to the "Technical Information"
bulletins for engineering changes
which have been introduced since
publication of this service manual.
Technical information bulletins
supplement the service manual and
parts list until revised editions are
issued.
The special servicing tools
mentioned in the descriptions are
listed in the chapter "Special
Servicing Tools" of this manual.
Use the part numbers to identify the
tools in the "STIHL Special Tools”
manual. The manual lists all special
servicing tools currently available
from STIHL.
Symbols are included in the text and
pictures for greater clarity.
The meanings are as follows:
In the descriptions:
:
= Action to be taken as
shown in the illustration
(above the text)
– = Action to be taken that is
not shown in the illustration
(above the text)
In the illustrations:
Pointer
Direction of movement
b
4.2 Reference to another
chapter, i.e. chapter 4.2
in this example
Service manuals and technical
information bulletins are intended
exclusively for the use of properly
equipped repair shops. They must
not be passed to third parties.
Servicing and repairs are made
considerably easier if the machine
is mounted on assembly stand (
2
)
5910 893 3100 with the aid of clamp
(
1
) 5910 890 8800.
The machine can then be swivelled
to the best position for the ongoing
repair.
VA
249RA!63
2
1
Always use original STIHL
replacement parts.
They can be identified by the
STIHL part number,
the
STIH)
logo and the
STIHL parts symbol
(
This symbol may appear alone on
small parts.
1.
Introduction