Echo CS-271T User manual

Ord. No. 401-37
CS-271T

INTRODUCTION
This service manual contains information for ser-
vice and maintenance of ECHO CHAIN SAW,
model CS-271T.
For systematic diagnosis, to avoid extra work,
time loss and to meet Emission regulation,
please refer to “Troubleshooting guide” that
describes problems, testing, remedies and
references. We recommend you make use of
Operator’s Manual and Parts Catalogue togeth-
er with this manual when servicing.
We are constantly working on technical improve-
ment of our products. For this reason, technical
data, equipment and design are subject to
change without notice. All specifications, illus-
trations and directions in this manual are based
on the latest product information available at the
time of publication.

TABLE OF CONTENTS
CS-271T 1
Page Page
1 SERVICE INFORMTION..................................................................................................................2
2 STARTER SYSTEM.........................................................................................................................7
3 IGNITION SYSTEM.......................................................................................................................13
4 FUEL SYSTEM..............................................................................................................................22
5 CLUTCH SYSTEM..................................... ...................................................................................36
6 CHAIN BRAKE SYSTEM..............................................................................................................39
7 SAW CHAIN LUBRICATION SYSTEM..........................................................................................43
8 ENGINE.........................................................................................................................................50
9 TOP HANDLE AND CONTROL SYSTEM .....................................................................................60
10 GUIDE BAR MOUNTING SYSTEM..............................................................................................62
11 MAINTENANCE GUIDE ..............................................................................................................64
INDEX................................................................................................................................................68

SERVICE INFORMATION CS-271T
2
Cutting devices
Guide bar Part No. 10A4CD3740 12A4CD3745
Called length in 10 12
Gauge in 0.043
Saw chain Number of drive links 40 45
Pitch in 3/8
Gauge in 0.043
1 SERVICE INFORMATION
1-1 Specications
Model CS-271T
Dimensions Length* mm(in) 257 (10.12)
Width mm(in) 228 (8.98)
Height mm(in) 210 (8.27)
Dry weight* kg(lb) 3.0 (6.6)
Engine Type YAMABIKO, air-cooled, two-stroke, single cylinder
gasoline engine
Rotation Clockwise as viewed from the output end
Displacement cm3(in3) 26.9 (1.641)
Bore mm(in) 35.0 (1.378)
Stroke mm(in) 28.0 (1.102)
Compression ratio 6.6
Carburetor Type Diaphragm horizontal-draft with acceleration pump
Model Walbro WT-1008
Venturi size-Throttle bore mm(in) 11.11-14.3 (0.437-0.563)
Ignition Type CDI (Capacitor discharge ignition) system
Digital Magneto
Spark plug BPM8Y (CANADA: BPMR8Y)
Starter Type Automatic rewind starter
Rope diameter x length mm(in) 3.5x700 (0.14x27.6)
Fuel Type Premixed two-stroke fuel
Mixture ratio 50 : 1 (2 %)
Gasoline Minimum 89 octane gasoline
Two-stroke air cooled engine oilISO-L-EGD (ISO/CD13738), JASO M345-FD
Tank capacity L (U.S..oz.) 0.24 (8.1)
Exhaust Mufer type Spark arrester mufer
Clutch Type Centrifugal type, 3-shoe slide with 3-tension spring
Guide bar / Saw chain lubrication type Adjustable automatic oil pump
Oil Tank capacity L (U.S..oz.) 0.16 (5.4)
Auto oiler Type Clutch related type
Sprocket Type Spur
Number of teeth 6
Pitch in 3/8
* Without guide bar and saw chain.
Oregon Saw chain 90SG

SERVICE INFORMATION
CS-271T 3
1-2 Technicaldata
Engine
Idling speed RPM 3,200 +/- 300
Wide open throttle speed* RPM 11,300 - 12,500
Clutch engagement speed RPM 4,400
Engagement Minimum†RPM 3,800
Compression pressure MPa (kgf/cm2) (psi) 0.85 (8.7) (124)
Ignition system
Spark plug gap mm(in) 0.6 - 0.7 (0.024 - 0.028)
Minimum secondary voltage at 1,500 RPM kV 17
Primary coil resistance MΩ 2.0 - 2.5
(Red Probe on stop terminal of module)
Secondary coil resistance Ω930 - 970
Pole shoe air gaps mm(in) 0.3 - 0.4 (0.012 - 0.016)
Ignition timing at 3,000 RPM °BTDC 16
at 8,000 RPM °BTDC 31
at 10,000 RPM °BTDC 32
Carburetor
Idle adjust screw initial setting turns in** 7/8
L mixture needle initial setting turns out 2
H mixture needle initial setting turns out 2 7/8
Test Pressure, minimum MPa (kgf/cm2) (psi) 0.05 (0.5) (7.0)
Metering lever height mm(in) 1.65 (0.06) lower than diaphragm seat
Chain oil discharge volume Adjustable: 1.5 - 13 (0.05 - 0.40)
(Factory set: 7 mL/min)
mL/min(U.S..oz./min)
BTDC: Before top dead center.
* With 12 in. guide bar and properly adjusted saw chain.
**Set idle adjust screw to the point that its tip contacts throttle plate before initial setting.
†If clutch engagement speed is lower than minimum RPM, replace clutch assembly with new one.
Cutting devices
Guide bar Part No. 10A0CD3740 12A0CD3745
Called length in 10 12
Gauge in 0.050
Saw chain Number of drive links 40 45
Pitch in 3/8
Gauge in 0.050
Oregon Saw chain 91VG as option

SERVICE INFORMATION CS-271T
4
1-4 Specialrepairingmaterials
Material Location Remarks
Adhesive Ball bearing outer / crankcase Loctite®#675 or equivalent
Liquid gasket Crankcase seams ThreeBond 1207D
Thread locking sealant
Starter pawl Loctite®#222, ThreeBond #1342 or equivalent
Ignition coil
ON-OFF switch Loctite®#242, ThreeBond #1324 or equivalent
Grease
Clutch needle bearing
Lithium based grease or ECHO XTended
ProtectionTM Lubricant
Rear handle cushion
Collar
Starter grip rope guide
Oil seal lip
Chain brake (metal contact part) Molybdenum grease (approx.1 gram)
1-3 Torquelimits
Descriptions Size kgf•cm N•m in•lbf
Starter Starter pawl M 5* 30 - 45 3 - 4.5 25 - 40
system Starter case M 5 10 - 20 1 - 2 9 - 18
Ignition Magneto rotor (Flywheel) M 8 250 - 290 25 - 29 220 - 255
system Ignition coil M 4* 30 - 45 3 - 4.5 25 - 40
ON-OFF switch M 3* 3 - 5 0.3 - 0.5 3 - 4
Spark plug M 14 130 - 170 13 - 17 113 - 150
Fuel Carburetor M 5 30 - 45 3 - 4.5 25 - 40
system Intake bellows
M 4 35 - 50 3.5 - 5 30 - 45
Clutch Clutch hub LM 10 230 - 260 23 - 26 200 - 230
Engine Crankcase M 5* 55 - 95 5.5 - 9.5 48 - 85
Engine mount M 5 70 - 110 7 - 11 60 - 95
Dust cover M 4 10 - 20 1 - 2 9 - 18
Eye plate M 4 10 - 20 1 - 2 9 - 18
Mufer M 5 70 - 100 7 - 10 60 - 90
Mufer cover M 5 10 - 20 1 - 2 9 - 18
Others Exhaust guide M 4 15 - 25 1.5 - 2.5 13 - 22
Auto-oiler M 4 20 - 35 2 - 3.5 18 - 30
Front handle M 5 20 - 40 2 - 4 18 - 35
Top handle M 4 10 - 20 1 - 2 9 - 18
Top handle assembly M 4 20 - 30 2 - 3 18 - 25
Cushion M 4 10 - 20 1 - 2 9 - 18
Brake cover M 4 10 - 20 1 - 2 9 - 18
Sprocket guard plate M 4 10 - 20 1 - 2 9 - 18
Brake lever (Hand guard) M 5 25 - 45 2.5 - 4.5 22 - 40
Chain catcher M 5 20 - 40 2 - 4 18 - 35
Guide bar stud M 8 180 - 250 18 - 25 160 - 220
Bolt (at guide bar mount) M 4 20 - 40 2 - 4 18 - 35
Regular bolt, nut and screw M 3 6 - 10 0.6 - 1 5 - 9
M 4 15 - 25 1.5 - 2.5 13 - 22
M 5 25 - 45 2.5 - 4.5 22 - 40
M 6 45 - 75 4.5 - 7.5 40 - 65
LM: Left-hand thread *Apply special repairing materials

SERVICE INFORMATION
CS-271T 5
Description mm (in)
A Cylinder bore When plating is worn and aluminum can be seen
BPiston outer diameter Min. 34. 91 (1.374)
CPiston pin bore Max. 8. 035 (0.3163)
DPiston ring groove Max. 1. 6 (0.063)
EPiston ring side clearance Max. 0. 1 (0.004)
FPiston pin outer diameter Min. 7. 98 (0.3142)
GPiston ring width Min. 1. 45 (0.057)
HPiston ring end gap Max. 0. 5 (0.02)
KCon-rod small end bore Max. 12. 00 (0.4724)
LCrankshaft runout Max. 0. 02 (0.001)
MSprocket bore Max. 12. 80 (0.5039)
NClutch drum bore Max. 55. 5 (2.19)
PSprocket wear limit Max. 0. 5 (0.02)
1-5 ServiceLimits
5K177 5K083 5K084 5K081
5K082 5K016 5K025
5K174 5K097
5K178
5K173 5K190 5K191
ABCD
F G H
K L M P
N
E

SERVICE INFORMATION CS-271T
6
1.35
0.4
1.65
1.5
Ignition Air Gap Gauge
#.014 = .35mm
P/N 91004
0
0.4
50
0.8
1.2
1.
MPa
0
1207D
PET-304
b
a
2600
1-6 Specialtools
1
3
452 6
9 10
11 1312 14
8
7
19
18 20
16, 17
Key Part Number Description Reference
1 900303 Tachometer PET-304 Measuring engine speed
289561279920 L-hex wrench (3 mm) Removing and installing hex. socket bolt (M4)
3 89561079920 L-hex wrench (4 mm) Removing and installing hex. socket bolt (M5)
4 89755902831 T-hex wrench (4 mm) Removing and installing hex. socket bolt (M5)
5 89750103938 Puller Removing magneto rotor
6 91004 Module air gap gauge Adjusting pole shoe air gaps
7 91037 Compression gauge Measuring cylinder compression
8 89770230131 Piston pin tool Removing and installing piston pin
9 89770106030 Bearing wedge Removing and crankshaft ball bearings
10 89756319830 Metering lever gauge Measuring metering lever height on carburetor
11 X686000000 ThreeBond 1207D Applying crankcase seam
12 89770511520 Bearing tool Replacing needle bearing on con-rod small end
13 91024 Pressure tester Testing crankcase leakages
14 89780079931 Spark tester Checking ignition system
15 89780330133 Pressure tester Testing carburetor and crankcase leakage
16 89801 Limiter cap removal tool Removal limiter cap (Left hand thread 2.5 mm)
17 89802 Limiter cap removal tool Removal limiter cap (Left hand thread 3.0 mm)
18 500-500 Welch plug tool Removing and installing welch plug tool
19 X640000011 Clutch tool Removing and assembling clutch assembly
20 89782616131 Pressure rubber plug Plugging intake port to test crankcase / cylinder leakages
21 89782812330 Pressure rubber plug Plugging intake port to test crankcase / cylinder leakages
22 89783516131 Pressure connector Checking crankcase and cylinder leakages
15
21
22

STARTER SYSTEM
CS-271T 7
2STARTERSYSTEM(i-30starter)
(A) Starter case
(B) Rewind spring
(C) Rewind spring case assembly
(D) Rope reel
(E) Power spring
(F) Pawl catcher
(G) Screw
(H) Starter rope
(J) Starter grip
838
Workingprinciple
1. When starter grip (J) is pulled, rope reel (D)
rotates.
2. The rotation force of rope reel (D) is transmitted
to pawl catcher (F) by power spring (E).
3. Pawl catcher (F) engages with starter pawls on
ywheel to turn crankshaft.
4. The load from compression pressure in cylinder
will keep crankshaft from rotating as power spring
(E) is twisted and accumulates energy.
5. As starter grip is pulled further, more energy is
stored in power spring (E) until accumulated energy
is enough to overcome compression pressure in
cylinder.
6. When accumulated energy in power spring (E)
overcomes the load from compression pressure in
cylinder, crankshaft is rotated.
7. Power spring absorbs compression resistance of
cylinder and snatch back of engine during starting
action.
8. When starter rope is released, rope reel (D) is
returned together with power spring (E) and pawl
catcher (F) by rewind spring tension.
9. After engine starts, starter pawls pivot outward by
centrifugal force and disengage from pawl catcher
(F).
Construction
1. Rewind spring case assembly (C) is installed
inside starter case (A).
2. Rope reel (D) with starter rope (H) is installed
on rewind spring case assembly.
3. Hook located on the backside of rope reel
engages with end (b) of rewind spring (B).
4. Power spring (E) is installed on rope reel.
5. Hook of power spring engages with rope reel
and top end hook (e) of power spring engages
with pawl catcher (F).
NOTE: Pawl catcher (F) of CS-271T has an
extended collar (f) to provide smooth power spring
(E) action and prevent power spring deformation.
(E) (D)
(A)
(C)
(b)
(e)
(B)
(H)
(F)
(G)
(J)
(f)

STARTER SYSTEM CS-271T
8
2-1 Disassemblingstarterassembly
1. Remove three screws and remove starter as-
sembly (A) from unit.
2. Pull out starter rope about 30cm (12in) and hold
rope reel (B) by hand. Loop excess rope in rope
reel notch (b) as shown.
3. Rotate rope reel (B) counterclockwise to release
tension of rewind spring.
4. Remove screw (C).
5. Remove pawl catcher (D) and power spring (E).
6. Remove rope reel (B) from starter case (F) slow-
ly to prevent rewind spring (G) from unwinding.
7. Remove rewind spring case assembly (H) from
starter case (F).
838
WARNING DANGER
Weareyeprotectionandtakecarewhen
removing starter drum. Rewind spring may
unwindsuddenlyandcausepersonalinjury.
A
B
C
D
F
GH
b
E
B

STARTER SYSTEM
CS-271T 9
2-2 Replacingstarterrope
1. Pull out and untie knot (A).
2. Pull knot (B) to remove rope from rope reel (C).
4. Make a knot (D) at end of starter rope and pass
the rope through hole of rope reel, then press the
knot (D) into recess as shown.
3. When installing a new starter rope, singe both
ends of the rope to prevent fraying.
5. Pass the other end of starter rope through start-
er case, from inside to outside.
6. Pass starter rope through starter grip. Set plate
(E) facing smooth side (e) to starter rope end.
Make a knot as shown.
7. Tighten knot. Push plate and knot into recess of
starter grip.
A
B
C
DD
E
e

STARTER SYSTEM CS-271T
10
2-3 Assemblingstarter
1. If rewind spring (A) is unwound from rewind
spring case (B), wind the spring inside case as
shown.
2. Carefully install rewind spring case assembly
(C) on starter case, matching hole (c) with post (D).
Hook (a) of rewind spring should contact with post
(E) of starter case.
3. Assemble rope reel (F) engaging hook (f1) with
hook (a) of rewind spring.
4. Check for proper engagement of rewind spring
and rope reel by turning rope reel (F) clockwise
and counterclockwise.
A
B
E
D
c
C
F
f1
a
a
F

STARTER SYSTEM
CS-271T 11
5. Install power spring (G), engaging hook (g1)
with rope reel groove (f2).
6. Install pawl catcher (H), engaging hole (h) with
power spring top end hook (g2).
NOTE: Make sure pawl catcher and rope reel have
ID mark “838” on them.
7. Reinstall screw (J) on starter post.
8. Pull out starter rope inside starter case. Rotate
rope reel clockwise several turns with starter rope
hooked at notch (f3) as shown. Hold rope reel to
prevent it from unwinding and pull out starter grip
to take the rope slack.
9. Pull starter several times to check rewind spring
tension. If starter is not rewinding fully, increase
spring tension by rotating rope reel one more turn
clockwise following above step (8).
10. Pull out starter rope all the way, and check that
rope reel can be rotated an additional half or more
turn clockwise as shown, to prevent rewind spring
from breaking.
11. If rope reel can not be turned clockwise, reduce
tension by rotating rope reel counterclockwise one
turn with starter rope hooked at notch (f3).
2-3 Assembling starter (continued)
83 8
83 8
H
G
g1
f2
h
g2
J
f3

STARTER SYSTEM CS-271T
12
1. Remove starter assembly from unit.
2. Loosen bolt (A) and remove washer, pawl (B),
spacer (C) and torsion spring (D). Replace dam-
aged or worn parts.
NOTE: When it is hard to loosen bolt, install clean
rope (E) in spark plug hole (F) to stop crankshaft
rotation and remove bolt easily.
3. Install torsion spring, spacer, pawl, washer and
bolt. To avoid pinching of torsion spring, install
these parts without setting the end (G) of torsion
spring on starter pawl. The bolt is pre-coated with
sealant on the thread. If the sealant is peeled off,
apply thread locking sealant (Loctite #242, Three-
Bond #1324 or equivalent).
4. Using ne wire (H) or appropriate tool, place the
end (G) of torsion spring on pawl (B), by hooking
and passing under pawl as shown. Remove fine
wire or tool.
5. Make sure pawl can move smoothly. If it does
not move smoothly, check parts for correct installa-
tion.
F
2-4 Replacingstarterpawl
D
C
B
A
H
B
G
G
E

IGNITION SYSTEM
CS-271T 13
(A) Flywheel (E) Spark plug cap
(B) Ignition coil (F) Switch lead
(C) Spark plug (G) Ground lead
(D) Spark plug cap coil (H) Ignition switch
3 IGNITION SYSTEM
(A)
(B)
(C)
(D)
(E)
(G)
(H)
(F)
(F)

IGNITION SYSTEM CS-271T
14
3-1 Troubleshootingguide
Not
OK
Not
OK
Not
OK
OK
OK
OK
Spark plug
Spark
plug cap/
coil
Ignition
switch
Clean /
Regap /
Replace.
Replace.
Start
OK
OK
S.T.
Not
OK
S.T.
Not
OK
Not
OK
S.T.
OK
S.T.
Not
OK Pole
shoe air
gaps
Replace.
Not
OK OK
Not
OK
S.T.
OK
OK
Replace
ignition
coil.
Leads
connections
Not
OK
OK
OK
Not
OK
S.T.
Repair /
Replace.
Not
OK
Remedy
Inspect
Not
OK
Flywheel
key
OK
R.T.*
End
Not
OK
Flywheel
magnet
Replace.
Not
OK
R.T.
Not
OK
OK
OK
Replace ignition coil and / or inspect other
systems.
Replace flywheel.
OK
OK
Adjust pole shoe air gaps.
(Inspect flywheel magnet
at the same time. Go to
Aif OK.)
S.T.
Not
OK
A
S.T.: Spark test.
R.T.: Running test including actual cutting.
OK
OK
Secondary
coil
resist-
ances

IGNITION SYSTEM
CS-271T 15
3-2 Testingspark
1. Remove air lter cover. Remove spark plug cap
from spark plug.
2. Connect spark plug cap to spark tester
99051130023 (A), and connect spark tester lead (B)
on spark plug as shown.
3. Screw in adjuster (a1) until the needle tips con-
tact. Turn out adjuster (a1) 4 turns to set spark
tester gap (a2) to 4 mm (0.16 in).
4. Turn ignition switch upward (“RUN” position).
Pull starter grip several times.
5. If spark is steady blue or white at the tester gap,
ignition system is considered good.
6. If no spark exists or spark is intermittent in
yellow, orange, or red, continue with further inspec-
tion.
DANGER
*Donot testnearsparkplugholewithout
spark pluginstalled,otherwisethereisa
chancetoignitefuelmixtureinsidecylinder.
*Donottouchmetal partsofsparktester
whileperformingthetesttoavoidreceiving
electricalshock.
*Donotchecksparkinareawheregasoline
isspilledorammablegasesmayexist.
3-3 Inspectingsparkplug
1. Remove spark plug to inspect for fouling,
cracked or broken insulator, cracked outer elec-
trode, or rounded center electrode. Clean or
replace spark plug as required.
2. Set spark plug gap (A) by bending outer elec-
trode (B).
Standard : 0.6 to 0.7 mm (0.024 to 0.028 in)
NOTE: Take care not to crack outer electrode
when bending.
3. If engine does not start with correct spark plug,
inspect if spark plug is wet or dry. If it is excessive-
ly wet or dry, inspect fuel system.
3K069
A
B
GASO
LINE
B
Aa1
a2

IGNITION SYSTEM CS-271T
16
3-4 Inspectingignitionswitch
1. Remove dust cover (A).
2. Disconnect ignition switch terminal (B) from pri-
mary lead terminal (C).
3. Connect one probe of Ohm-meter or multi-meter
to ignition switch terminal (B). Connect the other
probe to another ignition switch terminal (D).
4. When ignition switch is upward (“RUN” position),
tester should indicate innite resistance.
5. When ignition switch is in “STOP” position, tes-
ter should show that the circuit is in conducting
state (closed circuit).
6. If ignition switch is defective, replace with a new
one.
B
A
DB
C

IGNITION SYSTEM
CS-271T 17
3-5Replacingignitionswitch
1. Remove sprocket guard.
2. Remove cushion cap (A) by hooking hole (a)
with small hexagon wrench (B) etc., and remove
screw inside.
3. Remove four screws (C).
4. Remove top handle lid (D).
5. Disconnect terminals (e) and remove ignition
switch (E).
6. Assemble new ignition switch, passing leads
through three guides (F).
7. Connect terminals of ignition switch.
8. Pass leads under fuel lines.
9. Reassemble all removed parts.
A
B
F
D
E
e
a
C
F

IGNITION SYSTEM CS-271T
18
3-6 Inspectingignitioncoilresistanceandprimarylead
1. Remove air cleaner cover and starter assembly.
2. Connect one probe of Ohm-meter or multimeter
to spark plug cap coil in spark plug cap (A).
3. Connect the other probe to ignition coil core (B)
to measure secondary coil resistance. Second-
ary coil resistance should be in the range of 930 to
970 Ω.
4. If the meter reading indicates innite
resistance, remove spark plug cap and spark
plug cap coil, and measure resistance between the
conduction wire of high tension lead and ignition
coil core.
5. If the reading at step 3 or 4 is not in the range of
930 to 970 Ω, replace with a new ignition coil (Go
to “3-8 Replacing ignition coil”).
6. Remove dust cover. Disconnect primary lead
terminal (C) from ignition switch terminal (D).
7. Disconnect the other primary lead terminal (E)
from ignition coil.
8. Connect both probes of Ohm-meter or multime-
ter to both ends of primary lead as shown.
9. If the meter reading indicates innite resistance,
replace with a new primary lead.
A
B
C
D
E