Echo CS-305 User manual

X7503204801 X750006731
06/05
Chain Saw
InstructionManual
MODEL : CS-305
WARNING DANGER
Readrulesforsafeoperationandinstructionscarefully.ECHOprovidesanInstruction
ManualandaSafety Manual.Bothmustbereadandunderstoodforproperandsafe
operation.

2
RULES FOR SAFE OPERATION
A. Kickback Safety Precaution for Chain Saw Users
1. With a basic understanding of kickback, you
canreduceoreliminatetheelementofsurprise.
Suddensurprise contributestoaccidents.
2.Keep a good firm grip on the saw with both
hands, the right hand on the rear handle, and
theleft handon thefront handle,when theen-
gineisrunning.Useafirmgripwiththumbsand
fingersencirclingthechainsawhandles.Afirm
grip will help you reduce kickback and main-
taincontrolofthe saw.Don’t’letgo.
3. Make sure that the area in which you are cut-
ting is free from obstructions. Do not let the
noseof theguide barcontactalog,branch,or
anyotherobstruction whichcould behitwhile
youare operatingthesaw.
4. Cutathigh enginespeeds.
5. Donotoverreachorcutaboveshoulderheight.
6. Follow manufacturer’s sharpening and main-
tenanceinstructions forthesawchain.
7. Onlyusereplacement barsandchains speci-
fiedbythemanufacturerortheequivalent.
B. Other Safety Precautions
1. Donotoperateachainsawwithone hand!Se-
rious injury to the operator, helpers, bystand-
ers,or anycombinationofthesepersons may
resultfromone-handedoperation.Achainsaw
isintended fortwo-handed use.
2. Do not operate a chain saw when you are fa-
tigued.
3. Usesafetyfootwear;snug-fittingclothing;pro-
tectivegloves;andeye,hearingandheadpro-
tectiondevices.
4. Usecautionwhenhandlingfuel.Movethechain
sawatleast3m(10 feet)fromthe fuelingpoint
beforestarting theengine.
5. Donotallowotherpersonstobenearthechain
sawwhenstartingorcuttingwiththechainsaw.
Keepbystandersand animals outof the work
area.
6. Donotstart cuttinguntil youhaveaclearwork
area,securefooting,andaplannedretreatpath
fromthe fallingtree.
Copyright©2004 ByEcho,Incorporated
All Rights Reserved.
WARNING!
KICKBACKmay occurwhenthenoseortipofthe
guide bar touches an object, or when the wood
closesin andpinchesthe sawchain inthecut.
Tip contact in some cases may cause a lightning
fastreverse REACTION,Kickingtheguidebar up
andbacktowards theoperator. Pinchingthesaw
chainalong thetopoftheguide barmay pushthe
guide bar rapidly back towards the operator. Ei-
therofthesereactionsmaycauseyoutolosecon-
trol of the saw which could result in serious per-
sonalinjury.
The Kick Guard ®device is not installed on the
guide bar when you purchase your ECHO chain
saw.TheKickGuard®canbeusedinamajorityof
cuttingoperations,andisespeciallyrecommended
forbeginners,homeowners,orchainsawnovices.
Mostcuttingoperationscanbeaccomplishedwith
theKickGuard®in place.
Donotrelyexclusivelyuponthesafetydevicesbuilt
intoyoursaw.Asachainsawuser,youshouldtake
several steps to keep your cutting jobs free from
accidentor injury.

3
CONTENTS
Page
Rulesfor SafeOperation..................................................................................................2
TechnicalData .................................................................................................................4
Emission Data .................................................................................................................5
Description ......................................................................................................................5
Part Location and Description.........................................................................................6
PreparationforUse..........................................................................................................7
Fueland Lubricant............................................................................................................8
Operation.......................................................................................................................10
CuttingInstructions .........................................................................................................12
KickBack Safety Features..............................................................................................15
Maintenanceand Care...................................................................................................16
Chain and Guide Bar Combinations...............................................................................19
SettingtheSaw Chain....................................................................................................20
Troubleshooting..............................................................................................................21
Storage..........................................................................................................................22
Correct Use of Chain Brake ...........................................................................................23
ServicingInformation......................................................................................................24
7. Keepallpartsof yourbodyawayfromthesaw
chainwhentheengineis running.
8. Before you start the engine, make sure that
thesaw chainis notcontactinganything.
9. Carrythechain sawwiththeenginestopped,
the guide bar and saw chain to the rear, and
themufflerawayfromyourbody.
10.Donotoperate achainsaw thatisdamaged,
improperly adjusted, or not completely and
securely assembled. Be sure that the saw
chain stops moving when the throttle control
trigger is released.
11. Shutofftheenginebeforesettingthe chainsaw
down.
12.Useextremecaution whencuttingsmall size
brushand saplingsbecause slendermaterial
may catch the saw chain and be whipped to-
wardyou orpullyouoffbalance.
13.When cutting a limb that is under tension, be
alert for spring back so that you will not be
struck when the tension in the wood fibers is
released.
14.Keep thehandles dry,clean,and freeof oilor
fuelmixture.
15.Operatethechain sawonlyin well-ventilated
areas.
16.Do not operate a chain saw in a tree unless
youhavebeen specificallytrained todoso.
17.Allchainsawservice,otherthantheitemslisted
intheInstructionManualmaintenanceinstruc-
tions,shouldbeperformedbycompetentchain
saw service personnel. (For example, if im-
proper tools are used to remove the flywheel
or if an improper tool is used to hold the fly-
wheelinordertoremove theclutch,structural
damagetotheflywheelcouldoccurandcould
subsequentlycausethe flywheeltoburst.)
18.When transporting your chain saw, use the
appropriate guide bar scabbard.
19.SparkarrestormufflersapprovedtoSAEStan-
dard J335b are Standard on ECHO Chain
saws to reduce the possibility of forest fires.
Do not operate the chain saw with a loose or
defectivemuffler.Donotremovethe sparkar-
restorscreen.

4
TECHNICAL DATA
* Technical data subject to change without notice.
IMPORTANT
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5
DESCRIPTION
TheECHOproductyoupurchasedhasbeenfactorypre-assembledforyourconvenience.Duetopackaging
restrictions, guide bar and saw chain installation and other assembly may be necessary.
Afteropeningthe carton,checkfor damage. Immediatelynotifyyourretailer orECHODealer ofdamagedor
missing parts. Use the contents list to check for missing parts.
CONTENTS
1 - PowerHead
1 - GuideBar
1 - KickGuard
1 - Hex Head Bolt
1 - HexNut
1 - SawChain
1 - InstructionManual
1 - SafetyManual
1 - WarrantyRegistrationCard
1 - LimitedWarrantyStatement
1 - T-Wrench
1 - Echo Power Blend TM 2-stroke oil sample
EMISSION CONTROL
IMPORTANTENGINEINFORMATION
ENGINEFAMILY: 4EXHS.0334RA DISPLACEMENT: 30.1 CC
EMISSIONCOMPLIANCEPERIOD :300HRS.
THISENGINEMEETSU.S.EPAPAHSE 2EMISSIONREGULA-
TIONS FOR SMALL NONROAD ENGINE. REFER TO OWNER'S
MANUAL FOR MAINTENANCE SPECIFICATIONS AND
ADJUSTMENTS.
EMISSION DATA
PRODUCT EMISSION DURABILITY
The300 hour emission durabilitycompliance period isthe time span selected by the manufacturercertifying
theengineemissionsoutputmeetsapplicableemissionsregulations,providedthatapprovedmaintenance
proceduresare followed as listedin the MaintenanceSection of this manual.
EPA Phase 2
The emission control system for these engines are
EM(EngineModification).
An Emission Control Label islocated onthe engine. (These areEXAMPLES ONLY, information on label
variesbyengineFAMILY).

6
1. Fronthandle
2. Handguard
(Chainbrakeactuatinglever)
3. Sawchain
4. Guidebar
5. Chaincatcher
6. Sprocketguard
7. Muffler
8. Rearhandguard
9. Throttlecontrollockout
10. Throttlecontroltrigger
11. Aircleanercover
12. Chaintensionadjustmentscrew
13. Pull starter
14. Throttlecontrollatch
15. On / Off switch
16. Oil tank cap
17. Fuel tank cap
18. Purgebulb
19. Kick guard
20. Spark Plug
21. Choke
CS-305
PART LOCATION AND DESCRIPTION
12
3
4
5
7
8
9
11
14
15
16
17
18
6
10
12
13
19
13
20
21
21

7
PREPARATION FOR USE
WARNING DANGER
SawChainissharp!Alwaysweargloveswhenhandling
assembly, otherwise serious personal injury may result.
GUIDE BAR AND SAW CHAIN
• Removetwo guide barnuts (I)andremove sprocketguard
(J).
• Mount guide bar (G) on studs, and slide toward sprocket
to make saw chain installation easier.
• Install saw chain (H) as shown, with cutters on top of
guidebarfacingforward.
IMPORTANT
Becertaintensioner(K)fitsintoloweradjusterholebefore
tighteningguidebarnuts.
NOTE
Movechainbrakeleverfullyrearwardtoinstallsprocket
guardtosaw.
• Installsprocket guard(J), and tighten guide barnuts finger
tight.
• Adjust saw chain tension, as instructed in “Adjustment,
ChainTension.”
KICK GUARD®TO BAR INSTRUCTIONS
For saws with Kick Guard®P/N 2894901 and symmetri-
cal or asymmetrical low-kick type guide bars.
1. Install bolt (A) in rear hole (B) of Kick Guard®and
throughfront hole(C)in guidebar.
2. IMPORTANT:Dimple inKick Guard®(D)must engage
recess in guide bar (E).
3. Tighten nut (F) and bolt (A) until snug. Make certain Kick
Guard®isflushagainst guide bar.
G
H
J
K
I

8
L
ADJUSTMENT, CHAIN TENSION
• Removesparkplug lead.
•Loosen two guide bar nuts (I), if necessary.
• Hold the bar nose up, and turn the adjuster screw (L)
clockwise until the chain touches the bottom of the
bar.
• Tightenboth guide barnuts withbar nose held up.
IMPORTANT!
Tighten guide bar nuts to 90 – 110 kgf/cm (80 – 95
in. lbs.) DO NOT over-tighten nuts. Damage to saw
may result.
• Pull the saw chain around the guide bar by hand.
Reduce chain tension, if you feel tight spots.
• Keep chain properly tensioned at all times.
NOTE
Allchainsrequirefrequentadjustments.
FUEL AND LUBRICANT
FUEL STATEMENT
GASOLINE - Use89 Octane[R+M/2](midgrade orhigher)
gasoline or gasohol known to be good quality. Gasohol may
contain up to 10% Ethyl (grain) alcohol or 15% MTBE (methyl
tertiary-butylether).Gasoholcontainingmethyl(wood)alcohol
isNOTapproved.
Two Stroke Oil - A two-stroke engine oil meeting ISO-L-EGD
(ISO/CD13738) and J.A.S.O.FCStandards must beused.
EchobrandpremiumPowerBlendTM Universal 2-Stroke Oil
meetsthesestandards.Engine problems duetoinadequate
lubricationcaused by failure to use an ISO-L-EGDand J.A.S.O.
FC certified oil, such as Echo premium Power BlendTM, will void
the two-stroke engine warranty. (Emission related parts only
arecoveredfortwoyears,regardlessoftwo-strokeoilused,per
the statement listed in the Emission Defect Warranty Explana-
tion.)
IMPORTANT
Echopremium PowerBlendTM Universal 2-Stroke Oilmay be
mixed at 50:1 ratio for application in all Echo engines sold in
the past regardless of ratio specified in those manuals.
50
Oil
Gasoline

9
FUELTANK OILTANK
TANKINDICATION
IMPORTANT
Stored fuel ages. Do not mix more fuel than you expect to
use in thirty (30) days, ninety (90) days when a fuel stabi-
lizer is added.
Stored two-stroke fuel may separate.ALWAYS shake fuel
containerthoroughly beforeeachuse.
IMPORTANT
Spilled fuel is a leading cause of hydrocarbon emissions.
Some states may require the use of automatic fuel shut-
offcontainersto reduce fuelspillage.Contactyour ECHO
dealerfororderinginformation.
CHAIN LUBRICANT
Properlubrication ofthe chainwhile inoperation reducesfriction
between the chain and the guide bar to a minimum and assures
alonger servicelife.
• Use bar and chain oil of high quality for this purpose.
• Donot useused or reclaimedoil toavoid variousoiler
problems.
• Use ECHO bar and chain oil.
• When ECHO bar and chain oil is not available:
Use motor oil, etc.
• Usebar andchain oil ofthe followinggrades:
SAE NO. 30 ..... in summer
SAE NO. 10 ..... in winter or when cutting resinous trees.
• Whenrefueling, alsorefill chain oil.
MixingInstructions
1. Fillanapprovedfuelcontainerwithhalfoftherequired
amountofgasoline.
2. Addthe proper amountof 2-stroke oil togasoline.
3. Close container and shake to mix oil with gasoline.
4. Addremaininggasolineandremix.
5. Installfuelcontainer capand wipeany spilledfuel from
containerandsurroundingarea.
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SAGLIOSAGLIO
.laG.zo.lFretiL.cc
1
2
5
6.2
1.5
8.21
4
8
02
08
061
004
Fuel Mix Chart
50:1

10
Securely hold the saw.
OPERATION
B
C
A
WHEN THE ENGINE IS COLD
WARNING DANGER
Make sure bar and chain are not touching anything when
starting the saw.
• Movechain brake leverfully forwardtoengage chainbrake
beforestarting.
• Fill the fuel tank with fuel.
• Fill the chain oil tank with lubricant.
• Turnswitch (A) to“RUN” position(I).
• Pull choke (B) all the way out (closed position).
• Push purge bulb (C) 10 times.
• Pull starter handle several times until first firing sound is
heard. (Secure unit on ground with your knee or foot.) (5 -
6 pulls maximum.)
• Push choke (B) all the way in. (open position)
• Pullstarter handleagain.
NOTE
If engine does not start after 5 pulls, repeat instructions.
WHEN THE ENGINE IS HARD TO START
WARNING DANGER
Clutchengagesandchainmayrotatewhenengineisstarted
with throttle control latch engaged. Never use the throttle
controllatchforcutting.Use only whenstartingtheengine.
• Press throttle control lockout down, squeeze throttle
trigger, and push in throttle control latch.
• Pullstarter handle.
• When engine starts, immediately squeeze throttle trigger
to release the latch otherwise damage to clutch may
result.
NOTE
Do not pull starter rope out to the maximum possible
position.
Do not allow recoil handle to snap back against the
casing.

11
A
A
STARTINGWARM ENGINE
• Ensure that there is fuel and chain oil in the tanks. (If fuel
tankwas emptiedduring previousoperation, refilltankand
pushpurge bulb 10 times.)
• Turnswitch (A) to“RUN” position(I).
• Pullstarter handle.
• Choke may be used if necessary, but be sure to push it
back on first firing sound.
NOTE
If engine does not start after 5 pulls, use cold start
procedure.
RUNNING
WARNING DANGER
Thesaw chain shouldnot move at idle, otherwiseserious
personalinjury may result.
NOTE
Ifsaw chainmoves adjustcarburetor accordingto
“CarburetorAdjustment” instructions inthis manual,or
seeyour dealer.
• After engine starts, allow it to return to idle.
• Movechain brake leverfully rearwardtorelease chain
brake.
• Press throttle control lockout then gradually squeeze
throttletrigger to increase enginespeed.
• Sawchain startsmoving whenthe enginereaches
approximately4200 rpm.
• Ensureproper accelerationand lubricationofchain and
bar.
• Do not run the engine at high speed unnecessarily.
• Be sure that saw chain stops moving when throttle trigger
isreleased.
STOPPING
• Release throttle trigger and turn switch (A) to STOP (O)
position.
NOTE
If engine does not stop, pull choke out fully to stop
engine.
Checkand repairstop switch beforestarting theengine
again.

12
WARNING DANGER
Read the ECHO “CHAIN SAW SAFETY MANUAL” included
with your chain saw for additional cutting and safety instruc-
tions. Failure to obey all instructions may result in serious or
fatalinjuries.
In all circumstances the operation of the chain saw is a one-
man job. It is difficult at times to take care for your own safety,
so don’t assume the responsibility for a helper as well.After
youhave learned thebasic techniques ofusing the saw,your
best aid will be your own good common sense...
The accepted way to hold the saw is to stand to the left of the
sawwith yourleft hand onthe fronthandlebar andyour right
handon the rearhandle so youcan operate thethrottle trigger
withyour rightindex finger.
Before attempting to fell a tree, cut some small logs or limbs.
Becomethoroughly familiar with the controlsand there-
sponses of the saw.
Start the engine, see that it is running properly. Squeeze the
trigger to open the throttle wide open and start the cut. If the
chainis properlysharpened, the cutting should berelatively
effortless. It is not necessary to press down hard to make the
saw cut. Pushing the saw too hard will slow the engine and
cutting will actually be more difficult.
NOTE
Somematerial mayadversely affect the housings ofyour
ECHOchain saw.
(Example:PalmTreeAcid,fertilizer,etc.)Toavoid housing
deterioration,carefully removeallpacked sawdust around
clutchand guide bar area andwash withwater.
WARNING DANGER
Donot letthe tip ofthe bartouch anythingwhile the engine is
running.At cuttingspeed thechain ismoving ata highrate of
speed. Should the tip contact a limb or log while the chain is
moving,thetipwill bepushedupwardwith considerableforce.
This is known as kickback.Avoid it!
Kickback
CUTTING INSTRUCTIONS
GENERAL

13
2”
45°
2”
FELLING A TREE
DIRECTION
OFFALL
Direction of fall Hinge
Fellingcut
First cut
Notch
Second cut
One-third tree
diameter
LIMBING
WARNING DANGER
A falling tree can cause serious injury or damage any-
thingitmay hit- a car, ahouse,a fence,apower line,or
anothertree. There areways to makea tree fallwhere
you want it, so first decide where that is!
Beforecutting,clear the areaaroundthetree.Youwill need
goodfooting whileworkingand youshould beable towork
the saw without hitting any obstacles. Next, select a path
of retreat. When the tree begins to fall you should retreat
awayfromthe directionoffall ata45 degreeangleto avoid
the trunk kicking back over the stump.
Begin the cut on the side to which the tree is to fall. Cut a
notch about 1/3 of the way into the tree as shown. The
position of this notch is important since the tree will try to
fall “into” the notch. The felling cut is made on the side
oppositethenotchand atalevelabout 2”abovethebottom
ofthe notch. Do nottry to cutthrough to the notchwith the
fellingcut. Theremainingwood betweenthe notchcut and
felling cut (about 2”) will act as a hinge when the tree falls,
guiding it in the desired direction. When the tree starts to
fall,kill theengine, place thesaw onthe groundand make
your retreat quickly.
To fell big trees with a diameter exceeding twice the bar
length, start the notching cuts from one side and draw the
saw through to the other side of the notch. Start the back
cutonone sideofthetree, pivotingthesaw throughtoform
the desired hinge on that side.
Thenremove the saw for thesecond cut.Insert the sawin
the first cut, very carefully so as not to cause kickback.
Thefinal cutis madebydrawing thesaw forwardin thecut
to reach the hinge.
Limbing a fallen tree is much the same as bucking. Never
limbon the tree that youare standing.When limbing, cau-
tion is the word. Be careful of the tip touching other limbs.
Always use both hands.

14
BUCKING
Uphillposition
FINISHCUT
FIRSTCUT Board or flat stones
KICKBACK
• Improper thrust cutting.
• When the bar nose hits another tree, etc.
Don’t cut with the saw overhead or the bar in a vertical posi-
tion. If the saw should kick back you may not have good
enoughcontrol toprevent possibleinjury.
Bucking is the sawing of a log or fallen tree into smaller
pieces. There are a few basic rules which apply to all
buckingoperations.
Keep both hands on the handles at all times.
Support logs if possible.
When cutting on a slope or hillside, always stand uphill.
Keepin mindthat thewood isheavy andthat itwill bendand
pinchthe sawif improperlysupported.
The trunk will weaken at the point where you make the cut
unless the tree is lying on perfectly flat ground or supported
asshown.
If you make the cut with the tree on the ground, don’t let the
saw’s chain dig into the earth; it is harmful for the saw, and
you stand a good chance of being struck by flying debris.To
cutthe trunk,use thebucking andtwo-cut sequenceshown.
The first cut should be no deeper than one-third the trunk
diameter.
WARNING DANGER
KICKBACK IS DANGEROUS
Kickback is generated when the rotation of the chain is
arrestedfor somereason. Themost dangerous effect of
this action occurs when the nose of the bar contacts
anotherobject, thechain ismomentarily stopped and all
theenergyoftheenginethrowsthebarupwardsandback-
wardstowardsthe operator.
The chain saw industry and government agencies have
attempted to prescribe various safety devices, but the
best protection is to avoid kickback.
Comply with the Safety Precautions as listed on page 2
of this manual.

15
NOTE
UseECHOTM replacement guide bars.
Theseguide barsmay beconsidered tohave equivalentkickback reduction:
• Sprocket nose guide bars of the same length and nose radius, same pitch and having the same number of teeth.
• Ahard nose guide bar having the same length and nose radius as a sprocket nose bar.
• Low Kick Guard Link Type Saw Chain
The low kick, guard link chain must be maintained correctly. Follow instruction “SETTING THE CHAIN” in this Instruc-
tionManual.
• Front Hand Guard (Chain Brake Actuating Lever)
Thefront handle guard must be installed correctly and kept ingood condition.
• Chain Brake
Chainbrake must be maintained correctly.Follow instruction “CORRECTUSE OFCHAIN BRAKE” inthis Instruction
Manual.
• Kick Guard
Kickguard must be installedproperly. Followinstructions provided.
WARNING DANGER
Usingimproper replacementcomponents orremoving safetydevices mayresult inserious or fatalinjury.
Reduced nose
radius
DoubleGuardBar
INFORMATION
Kickback Safety Features
Thefollowing featuresare standard forthis modelas KickbackSafety Features.
• Double Guard Low Kick Type Guide Bar or Asymmetrical Low Kick Type Guide Bar
Note: Your saw chain can be used with either of these bars.

16
A
BC
D
E
G
I
MAINTENANCE AND CARE
AIRFILTER
• Checkbeforeeveryuse.
• Pull choke (A) all the way out (close position).
• Loosenboltandremoveaircleanercover(B)andfilter(C).
• Lightlybrush dust off filter, andinspect fordamage.
AUTOMATICOILER
• Thedischargevolumeoftheautomaticoilerisadjustedto3
to4cc/mm(@7000rpm)priortoshipmentfromthefactory.
• Always check oil discharge when in use.
• Turn adjusting screw (D) counter-clockwise to increase oil
volume,clockwisetodecreaseoilvolume.
F
OILSTRAINER
• Checkperiodically.
- Do not allow dust to enter into oil tank.
- Cloggedoilstrainer willaffectthenormallubricating
system.
- Pick it up through oil port.
- Ifthestrainer(F)isdirty,removecover(E),pullstrainer
out of oil tank, and wash it in suitable cleaning fluid.
- When the inside of the tank gets dirty, rinsing the tank
out with gasoline will clean it.
H
FUELSTRAINER
• Checkperiodically.
- Do not allow dust to enter fuel tank.
- Cloggedstrainerwillcausedifficultyinstartingengineor
abnormalitiesinengineperformance.
- Pickupthefuelstrainer(G)throughfuelinletportwitha
piece of steel wire, or the like.
- Whenthestrainerisdirty,replace,orwashitinsuitable
cleaningfluid.
- Whentheinsideofthefueltankisdirty,rinsingthetank
out with suitable cleaning fluid will clean it.
GUIDEBARANDOILHOLES
• Cleanaftereachuse
- Cleanthegrooves(H)oftheguidebarwith,forexample,
asmallscrewdriver.
- Clean oil holes (I) with a wire.
• Reverseguidebarperiodically.

17
SPROCKET
• Adamagedsprocket(J)willcauseprematuredamage
orwear ofsaw chain.
- Whenthe sprockethas wornout0.5mm (.020”)or
more, replace it.
• Checksprocketwhenyouinstallnewchain.Replaceit
ifworn.
• Clean sprocket, clutch, and bar mount area before
installationofbar.
IMPORTANT
Some tree sap and resins are corrosive. Thoroughly
washtheguidebarandsprocketareasaftereachuse,
then coat metal parts with light oil.
SPARK PLUG
• Checkperiodically
• Gap = 0.65mm (.026 in.)
• Replace if either electrode is worn, or if the insulator
is fouled by oil or other deposits.
• Torque = 145 – 155 kg*cm (125 – 135 in. lb.)
IMPORTANT
Donotover-torque.
COOLING SYSTEM CLEANING
• Removesparkpluglead.
• Removetwo(2)mufflercoverscrewsandmuffler
cover(A).
• Removefour(4)recoilstarterhousingscrewsand
starterhousing(B).
• Use a stiff bristle cleaning brush (do not us a metal
brush)toremovedirtfromcylinderfinsinmufflerand
ignition coil areas.
I
J
B
A

18
B
A
CARBURETOR ADJUSTMENT
Engine Break-In
Newenginesmustbeoperatedaminimumduration
oftwotanksoffuelbreak-inbeforecarburetoradjust-
mentscanbe made.During the break-inperiod your
engineperformancewillincreaseandexhaust
emissions will stabilize. Idle speed can be adjusted
asrequired.
BEFOREMAKINGADJUSTMENTS:
• Thecorrect spark plugmust be cleanand properly
gapped.
• Theair filterelementmust beclean andproperly
installed.
• Themufflersparkarrestorscreenandexhaustport
must be clear of carbon.
• Thestandardbarandchaincombination(see
page 4) must be installed to the power head, and
properlytensioned.
LOWALTITUDEADJUSTMENT
Enginesthathave been adjustedtooperate at high
altitudesmust be readjustedto operate properlyat
altitudesbelow2000feet.
1. Startengineandrunforseveralminutestoreachoperat-
ingtemperature.
2. Stopengine.Removegrommetcover(A)over“H”and“L”
limiterneedles.
3. Startengineandturnthehigh-speedneedlerich(CCW)
untiltheengineruns between 10,000and12,000RPM.
Thenturnthelow-speedneedlerich(CCW)untilthe
enginedoesnothesitate whenaccelerated.
DONOTREMOVELIMITERCAPS!
4. IdleSpeedAdjustment.
• Start engine and turn “idle” speed adjustment screw (B)
CW until the saw chain begins to move, then turn the
screwCCW until saw chainstops moving. Turnscrew
CCWan additional 1/4turn.
5. Accelerate to full throttle for 2-3 seconds to clear excess
fuelfrom engine thenreturn to idle.Accelerate to full
throttle to check for smooth transition from idle to full
throttle. If engine stops or stalls after full warm up return
theunit toyourauthorized ECHOdealerfor adjustment.
6.Installgrommetcover(A)over“H”and“L” limiter needles.
HIGHALTITUDEADJUSTMENT
Highaltitudeadjustmentmayberequiredforproperoperation
ofthisengineabove2000feet.
1. Startengineandrunforseveralminutestoreachoperat-
ingtemperature.
2. Stopengine.Removegrommetcover(A)over“H”and“L”
limiterneedles.
3. Start engine andturn the HI speed needle lean (CW) until
theenginerunsbetween10,000and12,000RPM.Then
turn the LO speed needle lean (CW) until the engine does
nothesitatewhenaccelerated.
DONOTREMOVELIMITERCAPS!
4. IdleSpeedAdjustment.
• Start engine and turn “idle” speed adjustment screw (B)
CW until the saw chain begins to move, then turn the
screwCCW until saw chainstops moving. Turnscrew
CCWan additional 1/4turn.
5. Accelerate to full throttle for 2-3 seconds to clear excess
fuelfrom engine thenreturn to idle.Accelerate to full
throttle to check for smooth transition from idle to full
throttle. If engine stops or stalls after full warm up return
theunit toyourauthorized ECHOdealerfor adjustment.
6.Installgrommetcover(A)over“H”and“L” limiter needles.

19
*Reducednoseradiussymmetricalbars(OREGONname—DoubleGuard)
WARNING DANGER
Useofreplacementsawchainand/orguidebarotherthanthatspecified,oroperationwithoutthe“tipguard”inplace,may
cause severe kickback resulting in serious injury.
Onlyusesawchaindesignatedas,“LOW-KICKBACK,”thatmeetstheANSIB175.1-2000Standard,andtheEchoguide
barspecified.
CHAIN AND GUIDE BAR COMBINATION
The following combinations may be used on CS-305.
Type: 90SG
HOLDFILEHOLDER
LEVEL
Depth
gauge
ONEFIFTHOFFILEDIAMETER
REMAINSABOVECUTTEREDGE
To sharpen other type chain,follow chainmanufacturer’sinstructions
30°
PUSHFILEAS SHOWN
Keep this angle
1/5
For setting saw chains, round file (4 mmø: 5/32”) and flat file are used.
• To keep correct position and correct angle, use the file holder.
-Round fileand flatfile areavailablefrom yourEcho Dealer.
• File cutters as below.
SETTING THE SAW CHAIN
IMPORTANT
If your kick guard is damaged or lost, contact your Echo dealer for a replacement. For the
name of the Echo dealer nearest you, Call: 1-800-432-ECHO (3246) or on the web at
www.echo-usa.com.
Refer to your Chain Saw Safety Manual for kick guard application information.
LEDOM RAB
HTGNEL
ELBUOD
RABDRAUG NIAHCWAS KCIK DRAUG
N/POHCE
)N/PMEO(
OHCE
.ONTRAP SKNILEPYTHCTIPEGUAG N/POHCE )N/PMEO
(
503-SC
"21 /105473421
)5473DC4A21( 540709154
GS09"8/3340. 1094982
94982
"41 /102573441
)2573DC4A41( 250709125
IMPORTANT
Chain and guide bar gauge size must be identical. Use Bar/Chain combinations shown in table
above.

20
Depth gauge
tool Remove
until flat
with tool
Round
off the
edge
30°
80° 50°
90
0.64 mm (0.025 in.)
Parallel
Number
indicates Chain
type
Number
indicates
Chaintype
90S
(SPROCKET)
(DRIVELINK)
• Properlyfiled cuttersare shownbelow.
(Top plate angle) (Sideplate angle) (Top plate cutting angle) (Depth gauge)
• When setting of the chain is finished, soak it in oil and wash away filings completely before using.
• When chain has been filed on the bar, supply sufficient oil to it, rotate the chain slowly to wash away the filings before
usingagain.
• If the chain saw is operated with filings clogged in the groove, the saw chain and the guide bar will be damaged
prematurely
• If the saw chain becomes soiled with resin, for instance, clean it with kerosene and soak it in oil.
AB
CHAIN TYPE AND SPROCKET PITCH
Sawchain shouldbe usedwith correspondingpitched
sprocket. To identify chain type and pitch of sprocket,
check as follows.
• Chain type number (A) is stamped on drive link.
• Sprocket pitch (B) is stamped on clutch drum.
• Placethe depth gaugetool firmly on guide bar so that depth gauge protrudes.Then file topof depth gaugewith flat file
until flat with top of the gauge tool.
- Besure to round off thefront edgeof the depth gauge.