Stihl BT 45 Manual

2 BT 45
This service manual contains
detailed descriptions of all the
typical repair and servicing
procedures for the BT 45 which is
based on the series 4140
powerhead.
You will find detailed descriptions of
procedures for servicing and
repairing engine components in the
service manual for the “Series 4140
Powerhead“.
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 also
supplement the parts list until a
revised edition is issued.
The special tools mentioned in the
descriptions are listed in 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)
b 4.2
Reference to another chapter, i.e.
chapter 4.2 in this example.
In the illustrations:
 Pointer
 Direction of movement
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.
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

Stihl BT 45 Specifications

General

Engine Type	2-stroke
Displacement	27.2 cc
Power Output	0.9 kW (1.2 hp)
Weight	5.2 kg
Power Source	Gasoline
No-Load Speed	0 - 300 rpm