Stihl 38 User Guide

							FS 38
English
29 Assembling the mowing head
NFit the empty spool in the mowing 
head.
If the spring (4) has popped out:
Npush it into the spool (2) until it 
engages in position with an audible 
click.
NMount the mowing head – see 
"Mounting the Mowing Head".Winding line onto spool
NUse green-coded nylon line with a 
diameter of 2.0 mm (0.08 in).
NCut two 2 m (6ft 6in) lengths of 
nylon line from the reel (special 
accessory).
NRotate the spool (2) 
counterclockwise until the two arrow 
points are in alignment.
NPush the straight end of each line 
through one sleeve (5) in the 
mowing head (3) until you feel a 
noticeable resistance – and then 
continue pushing as far as stop.NHold the mowing head steady.
NRotate the spool counterclockwise 
until the shortest line is about 10 cm 
(4 in).
NIf necessary, cut the longer line to a 
length of about 10 cm (4 in).
The mowing head is now full.
Schnur/LINE  1
681BA022 KN
24
Schnur/LINE  2
681BA023 KN
5
Schnur/LINE  13
32
681BA024 KN
Schnur/LINE  2
Schnur/LINE  1 
						

							FS 38
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30
STIHL AutoCut 5-2
Removing remaining nylon line
NOpen the mowing head – hold it 
steady with one hand and turn the 
cap (1) counterclockwise.
NDisengage the spool (2), take it out 
of the mowing head and remove the 
remaining line.
Winding line onto spool
A prewound spool (special accessory) 
may be used as an alternative to the 
following procedure.NUse green-coded nylon line with a 
diameter of 2.0 mm (0.08 in).
NCut two 3 m (9ft 9in) lengths of 
nylon line from the reel (special 
accessory).
NInsert the ends of each line (3) in the 
holes (4) in the spool.
NBend the ends of the lines over the 
edge of the holes to form a hook.NStraighten out the nylon lines and 
wind them tightly on to the spool – 
one nylon line in each chamber.
NEngage the ends of the lines in the 
notches (2).
Assembling the mowing head
NOTICE
Check that the spring is installed (see 
"Mounting the Mowing Head").
681BA008 KN
1
2
681BA009 KN
4
3
3
681BA010 KN
5
5 
						

							FS 38
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31 NThread the ends of the lines (6) 
through the sleeves (7) and push 
the spool (2) into the head so that it 
snaps into position.
The nylon lines must disengage from the 
notches (5) as the spool is pushed into 
position.
NPull out the ends of the lines as far 
as stop.
NMount the mowing head on the 
machine.
Replacing Cutting Blades
STIHL PolyCut
Always check the mowing head for signs 
of wear before installing new cutting 
blades.
WARNING
If there are signs of serious wear, 
replace the complete mowing head.
The thermoplastic cutting blades are 
referred to as "blades" in the following.
The mowing head is supplied with 
illustrated instructions for replacing the 
blades. Keep the instructions for the 
mowing head in a safe place.
WARNING
To reduce the risk of injury, always shut 
off the engine before installing the 
blades.
NRemove the mowing head.
NReplace blades as shown in the 
illustrated instructions.
NMount the mowing head on the 
machine.
Maintenance Work
STIHL recommends that you have 
servicing and repair work carried out 
exclusively by an authorized STIHL 
servicing dealer.
Fuel Pickup Body in Tank
NHave the pickup body in the fuel 
tank replaced every year.
Spark Arrestor in Muffler and Spacer
See "Main Parts" for positions of spark 
arrestor and spacer.
NIf the engine is down on power, 
have the spark arrestor in the 
muffler checked.
NCheck spacer for damage.
NHave damaged spacer replaced 
immediately.
7
681BA011 KN
2
6
6
,QVSHFWLRQVDQG0DLQWHQDQFH
E\HDOHU 
						

							FS 38
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32
Maintenance and Care
The following intervals apply to normal operating conditions only. If your daily work-
ing time is longer or operating conditions are difficult (very dusty work area, etc.), 
shorten the specified intervals accordingly.
before starting work
after finishing work or daily
after each refueling stop
weekly
monthly
every 12 months
if problem
if damaged
as required
Complete machineVisual inspection (condition, leaks)XX
CleanX
Replace any damaged partsX
Control handle Check operationXX
Air filterVisual inspectionXX
CleanXX
ReplaceX
Manual fuel pump (if fitted)CheckX
Have repaired by servicing dealer
1)X
Pickup body in fuel tankHave checked by servicing dealer
1)X
Have replaced by servicing dealer
1)XXX
Fuel tank CleanXX
CarburetorCheck idle adjustment – the cutting 
attachment must not rotateXX
Readjust idleX
Spark plugReadjust electrode gapX
Replace after every 100 operating hours
Cooling inletsVisual inspectionX
CleanX
Spark arrestor in mufflerHave checked by servicing dealer
1)XX
Have cleaned or replaced by servicing 
dealer
1)XX
SpacerCheckX
Have replaced by servicing dealer
1)XX 
						

							FS 38
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33
All accessible screws and nuts (not adjust-
ing screws)RetightenX
Cutting attachmentVisual inspectionXX
ReplaceX
Check tightnessXX
Safety labels ReplaceX
1)STIHL recommends an authorized STIHL servicing dealer. The following intervals apply to normal operating conditions only. If your daily work-
ing time is longer or operating conditions are difficult (very dusty work area, etc.), 
shorten the specified intervals accordingly.
before starting work
after finishing work or daily
after each refueling stop
weekly
monthly
every 12 months
if problem
if damaged
as required 
						

							FS 38
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341Loop Handle
2Sleeve
3Stop Switch
4Throttle Trigger Lockout
5Throttle Trigger
6Choke Lever
7Air Filter Cover
8Fuel Filler Cap
9Fuel Tank
10Machine Support
11Manual Fuel Pump
12Carburetor Adjusting Screws
13Starter Grip
14Spark Plug Boot
15Muffler (with Spark Arresting 
Screen)
16Spacer
17Line Limiting Blade
18Deflector
19Mowing Head
20Drive Tube
#Serial Number
Main Parts
2
18
6
5
437
9
10#
1311
1512
14
234BA020 KN
17
18
19
20
16
1 
						

							FS 38
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35
Definitions
1 Loop Handle
For easy control of machine during 
cutting work.
2Sleeve
Maintains minimum clearance 
between control handle and loop 
handle.
3 Stop Switch
Switches the engine's ignition off 
and stops the engine.
4 Throttle Trigger Lockout
Must be depressed before the 
throttle trigger can be activated.
5 Throttle Trigger
Controls the speed of the engine.
6 Choke Lever
Eases engine starting by enriching 
mixture.
7 Air Filter Cover
Covers and protects the air filter 
element.
8 Fuel Filler Cap
For closing the fuel tank..
9 Fuel Tank
For fuel and oil mixture.
10 Machine Support
For resting machine on the ground.
11 Manual Fuel Pump
Provides additional fuel feed for a 
cold start.
12 Carburetor Adjusting Screws
For tuning the carburetor.13 Starter Grip
The grip of the pull starter, for 
starting the engine.
14 Spark Plug Boot
Spark plug boot connects the spark 
plug with the ignition lead.
15 Muffler (with Spark Arresting 
Screen)
Muffler reduces exhaust noises and 
diverts exhaust gases away from 
operator.
Spark arresting screen is designed 
to reduce the risk of fire.
16 Spacer
Designed to reduce the risk of burns 
and fire.
17 Line Limiting Blade
Metal blade on the deflector which 
keeps the line of the mowing head 
at the proper length.
18 Deflector
The deflector is designed to reduce 
the risk of injury from foreign objects 
flung backwards toward the 
operator by the cutting attachment 
and from contact with the cutting 
attachment.
19 Mowing Head
The cutting attachment, i.e. mowing 
head, for different purposes.
20 Drive Tube
Encloses and protects the drive 
shaft between the engine and 
gearbox.
EPA / CEPA
The Emission Compliance Period 
referred to on the Emissions 
Compliance Label indicates the number 
of operating hours for which the engine 
has been shown to meet Federal 
emission requirements.
Category
CARB
The Emission Compliance Period used 
on the CARB-Air Index Label indicates 
the terms:
Engine
Single cylinder two-stroke engine
Specifications
A = 300 hours
B = 125 hours
C= 50hours
Extended = 300 hours
Intermediate = 125 hours
Moderate = 50 hours
Displacement: 27.2 cc 
(1.66 cu.in)
Bore: 34 mm (1.34 in)
Stroke: 30 mm (1.18 in)
Engine power to 
ISO 8893:0.65 kW 
(0.90 bhp) at 
8,300 rpm 
						

							FS 38
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36
Ignition System
Electronic magneto ignition
Fuel System
All position diaphragm carburetor with 
integral fuel pump
WeightUsers of this unit should carry out only 
the maintenance operations described 
in this manual. STIHL recommends that 
other repair work be performed only by 
authorized STIHL servicing dealers 
using genuine STIHL replacement parts.
Genuine STIHL parts can be identified 
by the STIHL part number, the 
{ logo and, in some cases, by 
the STIHL parts symbol K. The 
symbol may appear alone on small 
parts.
For repairs of any component of this 
unit’s air emissions control system, 
please refer to the air emissions 
systems warranty in this manual.Observe all country-specific waste 
disposal rules and regulations.
STIHL products must not be thrown in 
the garbage can. Take the product, 
accessories and packaging to an 
approved disposal site for environment-
friendly recycling.
Contact your STIHL servicing dealer for 
the latest information on waste disposal. Idle speed: 2,800 rpm
Cut-off speed (rated): 9,500 rpm
Max. output shaft 
speed (cutting 
attachment): 10,400 rpm
Spark plug (resistor 
type):Bosch WSR 6 F, 
NGK BPMR 7 A
Electrode gap: 0.5 mm (0.02 in)
Fuel tank capacity: 0.33 l (11.2 fl.oz)
dry, without cutting 
attachment and 
deflector 4.2 kg (9.3 lbs)
Maintenance and RepairsDisposal
000BA073 KN 
						

							FS 38
English
37 STIHL Incorporated Limited Warranty 
Policy
This product is sold subject to the STIHL 
Incorporated Limited Warranty Policy, 
available at 
http://www.stihlusa.com/warranty.html.
It can also be obtained from your 
authorized STIHL dealer or by calling 
1-800-GO-STIHL (1-800-467-8445).Not for California
Your Warranty Rights and Obligations
The U.S. Environmental Protection 
Agency (EPA) and STIHL Incorporated 
are pleased to explain the Emission 
Control System Warranty on your 
equipment type engine. In the U.S. new 
1997 and later model year small off-road 
equipment engines must be designed, 
built and equipped, at the time of sale, to 
meet the U.S. EPA regulations for small 
non road engines. The equipment 
engine must be free from defects in 
materials and workmanship which 
cause it to fail to conform with U.S. EPA 
standards for the first two years of 
engine use from the date of sale to the 
ultimate purchaser.
STIHL Incorporated must warrant the 
emission control system on your small 
off-road engine for the period of time 
listed below provided there has been no 
abuse, neglect or improper maintenance 
of your small off-road equipment engine.
Your emission control system includes 
parts such as the carburetor and the 
ignition system. Also included may be 
hoses, and connectors and other 
emission-related assemblies.
Where a warrantable condition exists, 
STIHL Incorporated will repair your 
small off-road equipment engine at no 
cost to you, including diagnosis (if the 
diagnostic work is performed at an 
authorized dealer), parts, and labor.Manufacturer's Warranty Coverage
In the U.S., 1997 and later model year 
small off-road equipment engines are 
w a r r a n t e d  f o r  t w o  y e a r s .  I f  a n y  e m i s s i o n -
related part on your engine is defective, 
the part will be repaired or replaced by 
STIHL Incorporated free of charge.
Owner's Warranty Responsibilities
As the small off-road equipment engine 
owner, you are responsible for the 
performance of the required 
maintenance listed in your instruction 
manual. STIHL Incorporated 
recommends that you retain all receipts 
covering maintenance on your small off-
road equipment engine, but STIHL 
Incorporated cannot deny warranty 
solely for the lack of receipts or for your 
failure to ensure the performance of all 
scheduled maintenance.
Any replacement part or service that is 
equivalent in performance and durability 
may be used in non-warranty 
maintenance or repairs, and shall not 
reduce the warranty obligations of the 
engine manufacturer.
As the small off-road equipment engine 
owner, you should be aware, however, 
that STIHL Incorporated may deny you 
warranty coverage if your small off-road 
equipment engine or a part has failed 
due to abuse, neglect, improper 
maintenance or unapproved 
modifications.
You are responsible for presenting your 
small off-road equipment engine to a 
STIHL service center as soon as a 
problem exists. The warranty repairs will 
be completed in a reasonable amount of 
time, not to exceed 30 days.
Limited WarrantySTIHL Incorporated Federal 
Emission Control Warranty 
Statement 
						

							FS 38
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38 If you have any questions regarding your 
warranty rights and responsibilities, 
please contact a STIHL customer 
service representative at 1-800-467-
8445 or you can write to
STIHL Inc.,
536 Viking Drive, P.O. Box 2015,
Virginia Beach, VA 23450-2015
www.stihlusa.com
Coverage by STIHL Incorporated
STIHL Incorporated warrants to the 
ultimate purchaser and each 
subsequent purchaser that your small 
off-road equipment engine will be 
designed, built and equipped, at the time 
of sale, to meet all applicable emissions 
regulations. STIHL Incorporated also 
warrants to the initial purchaser and 
each subsequent purchaser that your 
engine is free from defects in materials 
and workmanship which cause the 
engine to fail to conform with applicable 
emissions regulations for a period of two 
years.
Warranty Period
The warranty period will begin on the 
date the utility equipment engine is 
purchased by the initial purchaser. 
Product registration is recommended, 
so that STIHL has a means to contact 
you if there ever is a need to 
communicate repair or recall information 
about your product, but it is not required 
in order to obtain warranty service.
If any emission-related part on your 
engine is defective, the part will be 
replaced by STIHL Incorporated at no 
cost to the owner. Any warranted part 
which is not scheduled for replacement 
as required maintenance, or which is scheduled only for regular inspection to 
the effect of "repair or replace as 
necessary" will be warranted for the 
warranty period. Any warranted part 
which is scheduled for replacement as 
required maintenance will be warranted 
for the period of time up to the first 
scheduled replacement point for that 
part.
Diagnosis
You, as the owner, shall not be charged 
for diagnostic labor which leads to the 
determination that a warranted 
emissions part is defective. However, if 
you claim warranty for an emissions 
component and the machine is tested as 
non-defective, STIHL Incorporated will 
charge you for the cost of the emission 
test. Mechanical diagnostic work will be 
performed at an authorized STIHL 
servicing dealer. Emission test may be 
performed either at STIHL Incorporated 
or at any independent test laboratory.
Warranty Work
STIHL Incorporated shall remedy 
warranty defects at any authorized 
STIHL servicing dealer or warranty 
station. Any such work shall be free of 
charge to the owner if it is determined 
that an emissions warranted part is 
defective.
Any manufacturer-approved or 
equivalent replacement part may be 
used for any warranty maintenance or 
repairs on emission-related parts and 
must be provided without charge to the 
owner. STIHL Incorporated is liable for 
damages to other engine components 
caused by the failure of a warranted part 
still under warranty.The following list specifically defines the 
emission-related warranted parts:
–Air Filter
–Carburetor (if applicable)
–Fuel Pump
–Choke (Cold Start Enrichment 
System) (if applicable)
–Control Linkages
–Intake Manifold
–
Magneto or Electronic Ignition 
System (Ignition Module or 
Electronic Control Unit)
–Flywheel
–Spark Plug
–Solenoid Valve (if applicable)
–Injection Valve (if applicable)
–Injection Pump (if applicable)
–Throttle Housing (if applicable)
–Cylinder
–Muffler
–Catalytic Converter (if applicable)
–Fuel Tank
–Fuel Cap
–Fuel Line
–Fuel Line Fittings
–Clamps
–Fasteners
Where to make a Claim for Warranty 
Service
Bring the product to any authorized 
STIHL servicing dealer.