Echo SRM-251SB User manual

Grass Trimmer/Brush Cutter
Operator'sManual
MODEL SRM - 251SB
WARNING DANGER
Readrulesforsafeoperationandinstructionscarefully. ECHOprovidesanOperator's
ManualandaSafetyManual. Bothmustbereadandunderstoodforproperandsafe
operation.
X7502021901 X750008081
11/05

2
INTRODUCTION
Welcome to the ECHO family. This ECHO product was designed and manufactured to provide long life and on-the-job-
dependability. Read and understand this manual and the SAFETY MANUAL you found in the same package. You will
find both easy to use and full of helpful operating tips and SAFETY messages.
THE OPERATOR'SMANUAL
Read and understand this manual before operation. Keep it in a safe
place for future reference. Contains specifications and information for
operation, starting, stopping, maintenance, storage and assembly
specific to this product.
THE SAFETY MANUAL
Read and understand this manual before operation. Keep it in a safe
place for future reference. Explains possible hazards involved with the
use of Grass Trimmers and Brush Cutters and what measures you
should take to make their use safer.
Copyright©2005ByEcho,Incorporated
All Rights Reserved.
Specifications,descriptionsandillustrative material in
this literature are as accurate as known at the time of
publication, but are subject to change without notice.
Illustrations may include optional equipment and acces-
sories, and may not include all standard equipment.
TABLE OF CONTENTS
Introduction .................................................................... 2
- The Operator's Manual............................................. 2
- The Safety manual.................................................... 2
Safety .............................................................................. 3
- Manual Safety Symbols and Important Information 3
- InternationalSymbols .............................................. 3
- Personal Condition and Safety Equipment .............. 4
- EquipmentCheck ..................................................... 6
EmissionControl............................................................. 8
Description ..................................................................... 7
Contents ......................................................................... 9
Assembly ........................................................................ 9
- Power Head Shaft / Lower Shaft Assembly ............. 9
- PlasticShieldInstallation....................................... 10
- Nylon Head Installation......................................... 10
- Front Handle Installation ....................................... 11
Operation ...................................................................... 12
- OperationwithBlades ........................................... 12
- Fuel ........................................................................ 14
- StartingColdEngine .............................................. 15
- StartingWarmEngine............................................ 16
- Stopping Engine .................................................... 16
Maintenance ................................................................. 17
- SkillLevels ............................................................. 17
- Maintenance Intervals ........................................... 17
- AirFilter ................................................................. 18
- FuelFilter ............................................................... 18
- SparkPlug.............................................................. 19
- CoolingSystem...................................................... 19
- ExhaustSystem...................................................... 20
- Carburetor Adjustment .......................................... 21
- Lubrication............................................................. 23
- NylonLineReplacement ........................................ 24
- Sharpening Metal Blades....................................... 25
Troubleshooting ........................................................... 26
Storage.......................................................................... 27
Specifications................................................................ 28
ServicingInformation.................................................... 32
- Parts/SerialNumber ............................................... 32
- ECHOConsumerProductSupport......................... 32
- Service ................................................................... 32
- Warranty Card ....................................................... 32

GRASS TRIMMER/BRUSH CUTTER
OPERATOR'SMANUAL 3
INTERNATIONALSYMBOLS
Hot
Surface
Carburetor
Adjustment
-Idlespeed
Carburetor
Adjustment
- High speed
mixture
DESCRIPTION SYMBOLSYMBOL
"WARNING, SEE
OPERATOR'S
MANUAL
Weareye,ear
and head
protection
Emergency
Stop Fueland oil
mixture
FingerSevering
Carburetor
Adjustment
-Lowspeed
mixture
Primer
Bulb
Ignition
ON/
OFF
Wear hand and
foot protection
Safety/Alert
Keepbystandersandhelpers
away15m(50ft.).
DONOTsmoke
nearfuel.
DONOTallow
flamesorsparks
nearfuel.
DESCRIPTION SYMBOL DESCRIPTION SYMBOL DESCRIPTION
Choke Control
"Cold Start"
Position
(ChokeClosed)
Choke Control
"Run"
Position
(ChokeOpen)
Do not use
blades.String
lineonly
IMPORTANT
The enclosed message provides
information necessary for the protec-
tion of the unit.
NOTE
This enclosed message provides tips
for use, care and maintenance of the
unit.
Throughout this manual and on the product itself, you will find safety
alerts and helpful, informational messages preceded by symbols or key
words. The following is an explanation of those symbols and key
words and what they mean to you.
SAFETY
MANUAL SAFETY SYMBOLS AND IMPORTANT INFORMATION
This symbol accompanied by the words WARNING and
DANGER calls attention to an act or condition that can lead
to serious personal injury to operator and bystanders.
The circle with the slash symbol means whatever is shown
within the circle is prohibited.

4
Physical Condition
Your judgment and physical dexterity may not be good:
• if you are tired or sick,
• ifyouaretakingmedication,
• if you have taken alcohol or drugs.
Operate unit only if you are physically and mentally well.
Eye Protection
Wear eye protection that meets ANSI Z87.1 or CE requirements whenever you operate the unit.
Hand Protection
Wear no-slip, heavy-duty work gloves to improve your grip on the handle. Gloves also reduce the transmission of
machine vibration to your hands.
Hearing Protection
ECHO recommends wearing hearing protection whenever unit is used.
Proper Clothing
Wear snug fitting, durable clothing;
• Pants should have long legs, shirts with long sleeves.
• DONOTWEARSHORTS,
• DONOTWEARTIES,SCARFS,JEWELRY.
Wear protective hair covering to contain long hair.
Wear sturdy work shoes with nonskid soles;
• DONOTWEAROPENTOEDSHOES,
• DONOTOPERATEUNITBAREFOOTED.
Hot Humid Weather
Heavy protective clothing can increase operator fatigue which may lead to heat stroke. Schedule heavy work for early
morning or late afternoon hours when temperatures are cooler.
WARNING DANGER
Users of this product risk injury to themselves and others if the unit is used improperly and/or safety precautions
are not followed. Proper clothing and safety gear must be worn when operating unit.
PERSONAL CONDITION AND SAFETY EQUIPMENT
Extended Operation/Extreme Conditions
It is believed that a condition called Raynaud’s Phenomenon, which affects the fingers of certain individuals, may be
brought about by exposure to vibration and cold. Exposure to vibration and cold may cause tingling and burning
sensations, followed by loss of color and numbness in the fingers. The following precautions are strongly recom-
mended,becausetheminimumexposure,which might trigger the ailment, is unknown.
• Keep your body warm, especially the head, neck, feet, ankles,
hands, and wrists.
• Maintain good blood circulation by performing vigorous arm
exercises during frequent work breaks, and also by not smoking.
• Limit the hours of operation. Try to fill each day with jobs where
operating the unit or other hand-held power equipment is not
required.
• If you experience discomfort, redness, and swelling of the fingers
followed by whitening and loss of feeling, consult your physician
before further exposing yourself to cold and vibration.

GRASS TRIMMER/BRUSH CUTTER
OPERATOR'SMANUAL 5
WARNING DANGER
Do not operate this product indoors or in inadequately ventilated
areas. Engine exhaust contains poisonous emissions and can
cause serious injury or death.
Read the Manuals
• Provide all users of this equipment with the Operator’s Manual and
Safety Manual for instructions on Safe Operation.
Clear the Work Area
• Spectators and fellow workers must be warned, and children and
animalspreventedfrom comingnearerthan 15m(50 ft.)whilethe
unit is in use.
Keep a Firm Grip
• Hold the front and rear handles with both hands, with thumbs and
fingers encircling the handles.
Keep a Solid Stance
• Maintain footing and balance at all times. Do not stand on slippery,
uneven or unstable surfaces. Do not work in odd positions or on
ladders. Do not over reach.
Avoid Hot Surfaces
• Keep exhaust area clear of flammable debris. Avoid contact during
andimmediatelyafteroperation.
Repetitive Stress Injuries
It is believed that overusing the muscles and tendons of the fingers, hands, arms, and shoulders may cause soreness,
swelling, numbness, weakness, and extreme pain in those areas. Certain repetitive hand activities may put you at a high
riskfordeveloping a RepetitiveStressInjury(RSI). An extremeRSIcondition is CarpalTunnelSyndrome(CTS), which
could occur when your wrist swells and squeezes a vital nerve that runs through the area. Some believe that prolonged
exposure to vibration may contribute to CTS. CTS can cause severe pain for months or even years.
To reduce the risk of RSI/CTS, do the following:
• Avoid using your wrist in a bent, extended, or twisted position.
Instead try to maintain a straight wrist position. Also, when
grasping, use your whole hand, not just the thumb and index finger.
• Take periodic breaks to minimize repetition and rest your hands.
• Reduce the speed and force with which you do the repetitive
movement.
• Do exercise to strengthen the hand and arm muscles.
• Immediately stop using all power equipment and consult a doctor if
you feel tingling, numbness, or pain in the fingers, hands, wrists, or
arms. The sooner RSI/CTS is diagnosed, the more likely permanent
nerve and muscle damage can be prevented.

6
IMPORTANTENGINEINFORMATION
ENGINEFAMILY: 5EHXS.0254KE DISPLACEMENT: 25.4CC
EMISSIONCOMPLIANCE PERIOD: 300 Hours
THIS ENGINE MEETS U.S. EPA PH2 AND 2005 - 2006
CALIFORNIA EMISSION REGULATIONS FOR SORES.
REFER TO OWNER'S MANUAL FOR MAINTENANCE
SPECIFICATIONS AND ADJUSTMENTS.
EQUIPMENT CHECK
WARNING DANGER
Use only ECHO approved attachments. Serious injury may result from the use of a non-approved attachment
combination. ECHO, INC. will not be responsible for the failure of cutting devices, attachments or accessories which
have not been tested and approved by ECHO. Read and comply with all safety instructions listed in this manual and
safety manual.
• Check unit for loose/missing nuts, bolts, and screws. Tighten and/
or replace as needed.
• Inspect fuel lines, tank, and area around carburetor for fuel leaks.
DO NOT operate unit if leaks are found.
• Inspect shield for damage and ensure that the cut-off knife is
securely in place. Replace if either is damaged or missing.
• Check that the cutting attachment is firmly attached and in safe
operating condition.
• Check that front loop handle and shoulder strap/ or shoulder/
waist harness are adjusted for safe, comfortable operation. See
Assembly Section for proper adjustment.
EMISSION CONTROL
EPA Phase 2/California
The emission control system for this engine is EM/TWC (Engine
Modification and Catalyst).
PRODUCTEMISSIONDURABILITY
The 300 hour emission durability compliance period is the time span selected by the manufacturer certifying the
engine emissions output meets applicable emissions regulations, provided that approved maintenance procedures are
followed as listed in the Maintenance Section of this manual.
AnEmissionControlLabelis locatedonthe engine. (Thisisan EXAMPLEONLY,information onlabelvaries byengine
FAMILY).

GRASS TRIMMER/BRUSH CUTTER
OPERATOR'SMANUAL 7
1
4
5
7
8
2
3
9
10
11
6
12
DESCRIPTION
Locate these safety decals on your unit. Make sure the decals are legible and that you understand and follow the
instructions on them. If a decal cannot be read, a new one can be ordered from your ECHO dealer. See PARTS ORDER-
INGinstructionsforspecificinformation.
P/N 89022809560
P/N 89016054130
P/N 89016006361
Hot Decal (near muffler)
14
15
16
17
13
19
20
18
P/N 89016054130
P/N 89022809560
P/N X505001930
English Translation
Shaft Decal
P/N X505001930

8
1. POWERHEAD-IncludestheEngine,Clutch,FuelSystem,IgnitionSystemandRecoilStarter.
2. GRIP-Rear(righthand)handle.
3. THROTTLETRIGGERLOCKOUT-Thislevermustbeheldduringstarting.Operationofthethrottletriggeris
prevented unless throttle trigger lockout lever is engaged.
4. STOPSWITCH- "SLIDE SWITCH" mounted on top of the Throttle Trigger Housing. Move switch FORWARD to
RUN,BACKtoSTOP.
5. UPPERDRIVESHAFTASSEMBLY-IncludestheRear(RightHand)GripAssembly,Front(LeftHand)Handle
Assembly,UpperFlexibleDriveCable,DriveShaftAssemblyCouplerandPowerHead.
6. FRONTHANDLE/BARRIERBAR-TheFront(loop)handleislooselyassembledtotheDriveShaftassembly and
must be positioned for proper control and operator comfort. The Barrier Bar is used to restrict rearward movement of
the unit.
7. DRIVESHAFTCOUPLER-IncludesLocatorPinandClampingKnob.
8. NYLONCUTTINGATTACHMENT-Containsreplaceablenylontrimminglinethatadvanceswhenthetrimmerhead
is tapped against the ground while the head is turning at normal operating speed.
9. CUT-OFFKNIFE-Automatically trimslinetothecorrectlength:5"afterheadistappedontheground.Iftrimmeris
operated without a cut-off knife the line will become too long, the engine will overheat and engine damage may occur.
10. PLASTICDEBRISSHIELDASSEMBLY-Includedinplasticbag(co-pack).MUSTbeinstalledonunitbeforeuse,
see Assembly Instructions. Shield assembly includes the Cut-Off Knife and Safety Decal. Mounts on the Gear
Housing Assembly just above the cutting attachment. Helps protect the operator by deflecting debris produced
during the trimming operation. This shield must be replaced with the steel shield for blade use.
11. LOWERDRIVESHAFTASSEMBLY-IncludestheDebrisShieldAssembly,GearHousingAssembly,LowerFlexible
Drive Cable, Nylon Cutting Attachment and Safety Decal.
12. THROTTLETRIGGER-Springloadedtoreturntoidlewhenreleased. Duringacceleration,presstriggergraduallyfor
best operating technique.
13. SPARKPLUG-Providessparktoignitefuelmixture.
14. SPARKARRESTOR-CATALYTICMUFFLER/MUFFLER-Themufflerorcatalyticmufflercontrolsexhaustnoise
and emission. The spark arrestor screen prevents hot, glowing particles of carbon from leaving the muffler. Keep
exhaustareaclearofflammabledebris.
15. FUELTANK-Containsfuelandfuelfilter.
16. RECOILSTARTERHANDLE-Pullrecoilstarterhandleslowlyuntilstarterengages,thenquicklyandfirmly. When
engine starts, return handle slowly. DO NOT let handle snap back or damage to unit will occur.
17. FUELTANKCAP-Coversandsealsfueltankopening.
18. CHOKE - The choke control is located on the top of the air filter case. Move choke lever to "Cold Start" ( ) to
close choke for cold start. Move choke lever to "Run" ( ) position to open choke.
19. AIRCLEANER-Containsreplaceablefilterelement.
20. PURGEBULB-Pumpingpurge bulb before starting enginedrawsfreshfuelfrom the fuel tank primingthecarburetor
for starting. Pump purge bulb until fuel is visible and flows freely in the clear fuel tank return line. Pump purge bulb an
additional4 or5times.

GRASS TRIMMER/BRUSH CUTTER
OPERATOR'SMANUAL 9
CONTENTS
The ECHO product you purchased has been factory pre-assembled for your convenience. Due to packaging restrictions,
shield installation and other assembly may be necessary.
After opening the carton, check for damage. Immediately notify your retailer or ECHO Dealer of damaged or missing
parts. Use the contents list to check for missing parts.
___ 1 - Power Head w/Upper Drive Shaft Assembly
___ 1 - LowerDriveShaftAssembly
___ 1 - PlasticBag(co-pack)
___ - 1, Operator's Manual
___ - 1, Safety Manual
___ - 1, Warranty Registration Card
___ - 1,LimitedWarrantyStatement
___ - 1,Plastic shield
___ - 1,T-wrench
___ - 1,Lockingtool
___ - 1,4mmHexwrench
___ - 1,NylonTrimmerHead
___ - 1,HandleBracket,Bottom
___ - 1, Safety Glasses
___ - 1,2-StrokeOilSample
___ - 1,Shieldplate
___ - 3,5x16mmscrews(shieldmtg.)
Tools Required: None
Parts Required: PowerHeadShaft,LowerShaftAssembly
1. Set Power Head/Shaft Assembly on a level surface.
2. Pull locator pin (A) out, and turn counter-clockwise 1/4 turn to lock-
out position.
3. Carefully fit attachment drive shaft assembly into coupler (B) to
decal assembly line (C), making sure that the inner lower drive shaft
engages into the square upper drive shaft socket.
NOTE
Lower bearing housing and head assembly must be in line with the
engine.
ASSEMBLY
POWER HEAD SHAFT / LOWER SHAFT ASSEMBLY
D
A
A
B
D
B

10
C
PLASTIC SHIELD INSTALLATION
(for Nylon Line Operation)
Tools Required: Screwdriver.
Parts Required: PlasticShield,ShieldPlate,three(3)5mmx16mm
screws.
NOTE
The plastic shield is for use with the Nylon Line Head only.
Install Metal Shield when using plastic or metal blades.
4. Rotate locator pin (A) 1/4 turn clockwise to engage lower shaft
hole. Insure locator pin is fully engaged by twisting lower drive
shaft. Locator pin should snap flush in coupler. Full engagement will
prevent further shaft rotation.
5. Secure lower shaft assembly to coupler by tightening clamping
knob(D).
1. Remove plastic sleeve and upper plate (A) from PTO shaft.
2. Install the shield on the bottom of the bearing housing flange.
3. Place shield plate (B) on shield, align holes and install three (3)
5x16mmscrews.
4. Install upper plate (A).
B
A
NYLON LINE HEAD INSTALLATION
Tools Required: HeadLockingTool,
Parts Required: NylonLineHead.
1. Be sure upper adaptor plate remains on PTO shaft.
2. Align locking hole in upper plate with notch in edge of gear housing
and insert head locking tool (C).
3. Thread line head onto shaft by turning it counter clockwise until
head is tight against upper plate.
4. Remove head locking tool.
C