Echo CS-370ES Mounting instructions

CS-370ES01-36E-00 1
INTRODUCTION
We are constantly working on technical
improvement of our products. For this reason,
technical data, equipment and design are
subject to change without notice. All
specifications, illustrations and directions in
this SERVICE DATA are based on the latest
products information available at the time of
publication.
0
CONTENTS
page
1 SERVICE INFORMATION ............................. 2
1-1 Specification ............................................... 2
1-2 Technical data ............................................ 3
1-3 Torque limits ............................................... 4
1-4 Special repairing materials......................... 4
1-5 Service limits .............................................. 5
1-6 Special tools ............................................... 6
2 CARBURETTOR ADJUSTMENT PROCEDURE . 7
2-1 General adjusting rules .............................. 7
2-2 Presetting idle adjust screw, L mixture needle
and H mixture needle ........................................ 7
2-3 Adjusting carburettor .................................. 9
Reference No. 01-36E-00
ISSUED: 200703
INDEX

SERVICE INFORMATION CS-370ES
2
1 SERVICE INFORMATION
1-1 Specifications
Model CS-370ES
Dimensions Length* mm(in) 393 (15.5)
Width mm(in) 245 (9.6)
Height mm(in) 277 (10.9)
Dry weight* kg(lb) 4.6 (10.1)
Engine Type KIORITZ, air-cooled, two-stroke, single cylinder
Rotation Clockwise as viewed from the output end
Displacement cm3(in3) 36.3 (2.22)
Bore mm(in) 38.0 (1.50)
Stroke mm(in) 32.0 (1.26)
Compression ratio 7.6
Carburetor Type Diaphragm horizontal-draught, with auto-return choke**
Model Walbro WT-820A
Venturi size-Throttle bore mm(in) 13.5 - 15.85 (0.532 - 0.624)
Ignition Type Digital Magneto : CDI system
Spark plug BPMR8Y
Starter Type ES (effortless)-start
Rope diameter x length mm(in) 3.0 x 900 (0.14 x 35.4)
Fuel Type Premixed two-stroke fuel
Mixture ratio 50 : 1 (2 %)
Petrol Minimum 89 octane petrol
Two-stroke air cooled engine oilISO-L-EGD (ISO/CD13738), JASO FC
Tank capacity L (U.S.fl.oz.) 0.41 (13.9)
Clutch Type Centrifugal, 3-shoe slide with 3-tension spring
Guide bar / Saw chain lubrication type Automatic with volume adjuster
Oil Tank capacity L (U.S.fl.oz.) 0.28 (9.5)
Auto oiler Type clutch related type
Sprocket Type Spur
Number of teeth 6
Pitch in 3/8
Cutting devices
Guide bar Type 30RC50M-3/8 35RC50M-3/8
Called length cm 30 35
Gauge in 0.050
Saw chain Type OREGON 91VG
Number of drive links 47 53
Pitch in Low profile 3/8
Gauge in 0.050
* Without guide bar and saw chain.
** Auto-return choke is on switch bracket.

SERVICE INFORMATION
CS-370ES 3
1-2 Technical data
Engine
Idling speed r/min 2400 - 2900
Wide open throttle speed* r/min 11500 - 12500
Clutch engagement speed r/min 3800 - 4300
Compression pressure MPa (kgf/cm2) (psi) 1.02 (10.4) (148)
Ignition system
Spark plug gap mm(in) 0.6 - 0.7 (0.024 - 0.028)
Minimum secondary voltage at 1000 r/min kV 15
Secondary coil resistance kΩ1.5 - 2.2
Pole shoe air gaps mm(in) 0.3 - 0.4 (0.012 - 0.016)
Ignition timing at 3000 r/min °BTDC 10
at 8000 r/min °BTDC 32
at 10,000 r/min °BTDC 34
at 12,500 r/min °BTDC 32
Carburetor
Idle adjust screw initial setting turns in** 1 5/8
L mixture needle initial setting turns back 1 1/4
H mixture needle initial setting turns back 2 3/8
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 at 7000 r/ min Adjustable : 1.5 - 13 (0.05 - 0.40)
mL/min(U.S.fl.oz./min) (Factory set 7 mL/min)
BTDC: Before top dead center.
* With 35 cm guide bar and saw chain.
** Set idle speed screw to the point that its tip just contacts throttle plate before initial setting.

SERVICE INFORMATION CS-370ES
4
1-3 Torque limits
Descriptions Size kgf•cm N•m in•lbf
Starter Starter pawl M 5 40 - 60 4 - 6 35 - 50
system Starter case M 5** 25 - 35 2.5 - 3.5 22 - 30
Ignition Magneto rotor (Flywheel) M 8 250 - 290 25 - 29 220 - 250
system Ignition coil M 5 40 - 60 4 - 6 35 - 50
Ignition switch M 14 15 - 30 1.5 - 3 13 - 26
Spark plug M 14 150 - 170 15 - 17 130 - 150
Fuel Carburettor M 5 30 - 45 3 - 4.5 26 - 40
system carburetor elbow M 5** 20 - 30 2 - 3 17 - 26
Intake bellows M 5 30 - 45 3.0 - 4.5 26 - 40
Clutch Clutch hub LM 10 300 - 400 30 - 40 260 - 350
Engine Crankcase*** M 5* 70 - 110 7 - 11 60 - 95
Engine mount M 5 70 - 110 7 - 11 60 - 95
Muffler M 5 80 - 110 8 - 11 70 - 95
Cylinder cover M 5 25 - 45 2.5 - 4.5 22 - 40
Others Auto-oiler M4 20 - 35 2.5 - 3.5 17 - 30
Front handle M 5** 45 - 65 4.5 - 6.5 40 - 55
Rear handle assembly M 5 30 - 50 3 - 5 26 - 45
M 4 35 - 50 3.5 - 5 30 - 45
Handle lid M 4 10 - 20 1 - 2 9 - 17
Brake lever (Hand guard) M 5** 10 - 20 1 - 2 9 - 17
M 4** 45 - 65 4.5 - 6.5 40 - 55
Sprocket guard plate M 4** 10 - 20 1 - 2 9 - 17
Chain catcher M 5 45 - 60 4.5 - 6 40 - 52
Guide bar M 8 200 - 230 20 - 23 175 - 200
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
1-4 Special repairing materials
Material Location Remarks
Adhesive Ball bearing outer / crankcase
Pulse pipe joint Loctite #675 or equivalent
Cushions Loctite #424, ThreeBond #1741 or equivalent
Liquid gasket Crankcase seams Loctite #515 or equivalent
Grease Auto-oiler worm
Clutch needle bearing
Handle cushions Lithium based grease
Rewind spring
Starter center shaft
Chain brake (metal contact part) Molybdenum grease (approx. 1 gram)
LM: Left-hand thread *Apply thread locking sealant (See below) ** Tapping screw
*** The torque differences among four bolts should not exceed 20 kgf•cm (2N•m, 17in•lbf) on crankcase

SERVICE INFORMATION
CS-370ES 5
Description mm (in)
A Cylinder bore When plating is worn and aluminum can be seen
B Piston outer diameter Min. 37. 91 (1.493)
C Piston pin bore Max. 9. 075 (0.3573)
D Piston ring groove Max. 1. 6 (0.063)
E Piston ring side clearance Max. 0. 1 (0.004)
F Piston pin outer diameter Min. 8. 98 (0.3535)
G Piston ring width Min. 1. 45 (0.057)
H Piston ring end gap Max. 0. 5 (0.02)
K Con-rod small end bore Max. 12. 025 (0.4734)
L Crankshaft runout Max. 0. 05 (0.002)
M Sprocket bore Max. 13. 07 (0.5146)
N Clutch drum bore Max. 71. 5 (2.81)
P Sprocket wear limit Max. 0. 5 (0.02)
1-5 Service Limits
5K173
5K280
5K174 5K190
5K016 5K042
5K277 5K278
5K191
5K279
1234
5K275
5K276
ABCD
FGH
KLMP
N
E

SERVICE INFORMATION CS-370ES
6
1.35
0.4
1.65
1.5
a
20
40
60
80 120
140
160
180
20
100
IgnitionAirGapGauge
#.014=.35mm
P/N91004
91019
1-6 Special tools
145 2
69
10 11 1312
14 16
3
8
a = 3 mm
a = 4 mm
7
Key Part Number Description Reference
1 990511-30017 Tachometer PET-1000 Measuring engine speed
2 895612-79920 L-hex wrench (3 mm) Removing and installing hex. socket bolts (M4)
3 895610-79920 L-hex wrench (4 mm) Removing and installing hex. socket bolts (M5)
4 897501-03938 Puller Removing magneto rotor
5 897505-16133 Clutch tool Removing and assembling clutch assembly
6 91007 Compression gauge Measuring cylinder compression
7 897702-30131 Piston pin tool Removing and installing piston pin
8 897701-06030 Bearing wedge Removing and crankshaft ball bearings
9 897563-19830 Metering lever gauge Measuring metering lever height on carburetor
10 897708-19835 Worm puller Removing auto-oiler worm
11 Y089-000010 Worm inserter Installing auto-oiler worm : Crankshaft thread LM8x1.25
12 897726-09130 Oil seal tool Installing oil seals
13 897800-79931 Spark tester Checking ignition system
14 897803-30133 Pressure tester Testing carburettor and crankcase leakage
15 91019 Limiter cap tool Removing and installing limiter cap
16 500-500 Welch plug tool Removing and installing welch plug tool
17 990610-00051 Loctite #515 Applying crankcase seam
18 91004 Module air gap gauge Adjusting pole shoe air gaps
18
15 17

SERVICE INFORMATION
CS-370ES 7
H
L
B
AA
B
2 CARBURETTOR ADJUSTMENT PROCEDURE
2-1 General adjusting rules
A. Before starting the unit for adjustment, check the following items.
1. The correct spark plug must be clean and properly gapped.
2. The air filter element must be clean and properly installed.
3. The muffler exhaust port must be clear of carbon.
4. The fuel lines, tank vent and fuel filter are in good condition and clear of debris.
5. The fuel is fresh ( > 89 octane : RON) and properly mixed at 50 : 1 with “ISO L-EGD” or “JASO-FC” 2-
stroke oil.
6. The recommended bar and chain must be installed, and properly tensioned.
NOTE : In order to achieve proper carburettor adjustment, 30 or 35 cm bar and chain should be installed
on the unit. Otherwise serious engine damage will occur due to overspeeding.
B. Set L and H mixture needles full anticlockwise. Start and run engine for two minutes alternating engine
speed between WOT for 5 seconds and idle for 5 seconds. Adjust idle speed screw to 2,700 +/- 150 r/min.
Adjust H mixture needle to 12,000 +/- 500 r/min. If engine does not run correctly after this adjustment,
proceed to the next step 2-2.
IMPORTANT : After adjusting carburettor according to the steps 2-2 and 2-3, the limiter cap(s) must
be installed on L and H mixture needle(s) to comply with Emission Directive.
2-2 Presetting idle adjust screw, L mixture needle and H mixture needle
Parts Required : (2) P/N P003-000010 limiter caps.
1. Turn the L and H mixture needles anticlockwise
to rich side stop to align limiter cap tab (A) with
locating slot (B), using 3 mm blade screwdriver.
NOTE : If cap tabs (A) misalign with locating slots
(B), there is a chance to strip thread.
(continued)

SERVICE INFORMATION CS-370ES
8
2-2 Presetting idle adjust screw, L mixture needle and H mixture needle (continued)
2. Screw threaded end of limiter cap removal tool
91019 with 2.5 mm left-hand thread into center hole
of limiter cap anticlockwise until tab of the limiter
cap just comes out of the locating slot.
NOTE : DO NOT COMPLETELY REMOVE LIMITER
CAP FROM CARBURETTOR!
If the limiter cap was pulled out completely, there
is a chance that the other mixture needle would turn
and limiter cap tab would misalign with locating slot
when screwing the limiter cap removal tool into
center hole of the limiter cap. As a result, the thread
of the limiter cap would be stripped. Use 3 mm
diameter thread wood screw to remove the stripped
limiter cap.
3. Remove the limiter cap removal tool from the
limiter cap by turning the tool clockwise, leaving the
limiter cap in place.
4. Screw threaded end of limiter cap removal tool
91019 into center hole of the other limiter cap
anticlockwise until the limiter cap is removed from
the mixture needle completely. Remove the limiter
cap from limiter cap removal tool turning clockwise,
and screw thread of limiter cap removal tool 91019
into center hole of previous limiter cap to pull out
completely.
5. Turn L and H mixture needles clockwise until
lightly seated, and then turn out both mixture needles
following turns.
L mixture needle : 1 1/4, H mixture needle : 2 3/8
NOTE : If needles are forced during seating, damage
to carburettor may occur.
6. Remove air filter cover and air filter to see that
idle adjust screw contacts the throttle plate. Turn
idle adjust screw anticlockwise and set the screw
until the tip just contacts the throttle plate. Then turn
idle adjust screw 1 5/8 turns clockwise. Reinstall air
filter, and air filter cover.

SERVICE INFORMATION
CS-370ES 9
H
L
A
B
B
A
2-3 Adjusting carburettor
1. Start engine and warm it up at idle for one minute.
Turn H mixture needle anticlockwise until engine
speed drops to approx. 11,000 r/min.
2. Warm it up well for 100 sec alternating engine
speed between WOT (Wide Open Throttle) for 5
seconds and idle for 5 seconds .
NOTE : Do not run engine at high speed without
load longer than 5 seconds, or engine damage may
occur.
3. Adjust L mixture needle with 3 mm blade
screwdriver to reach maximum engine speed just
before lean drop off.
4. Set idle engine speed to 3,800 r/min by turning idle adjust screw. Engine speed should be stable at
3,800 +/- 50 r/min after idle adjust screw adjustment.
5. Turn L mixture needle anticlockwise reducing engine idle speed 1,200 r/min to set idle speed at 2,600
r/min. The engine idle speed range is 2,500 - 2,800 r/min.
NOTE : Engine speed must be allowed to stabilize a minimum of 20 seconds after each adjustment of L
mixture needle to assure accurate tachometer readings.
6. Make sure WOT engine speed is approx. 11,000 r/min. If WOT engine speed is over 11,000 r/min, turn
H mixture needle anticlockwise until engine speed drops to approx. 11,000 r/min. Turn H mixture needle
1/8 turn increments clockwise at idle engine speed, then squeeze throttle trigger and check WOT engine
speed. If the WOT engine speed is less than 11,500 r/min, turn H mixture needle 1/8 turn clockwise again,
and check WOT engine speed. The final WOT engine speed should fall within the11,700 to 12,300 r/min
range.
7. After adjusting carburettor, screw new limiter cap
on the thread of the limiter cap removal tool 91019
(C) anticlockwise approx. 2 turns as shown, and put
the limiter caps on L and H mixture needles
respectively. And then press the caps on L and H
mixture needles with opposite side of the limiter cap
tool (C).
NOTE : Align the limiter cap’s tabs (A) with locating
slots (B) in extended housing of carburettor.
IMPORTANT : The limiter caps must be installed L and H mixture needles to comply with Emission
Directive.
8. Start engine, and verify engine idle speed ranges from 2,400 to 2,900 r/min, and WOT engine speed
ranges from 11,500 to 12,500 r/min. Make sure chain does not rotate when engine is idling. When final
adjustment is completed, the engine should idle, accelerate smoothly, and attain WOT per above
specification.
NOTE : Initial carburettor setting (idle adjust screw, L and H mixture needles) shown on page 3 and 8 is
to start the engine after restoration or carburettor change. Idle adjust screw, L and H mixture needles turn
for designated engine revolution through procedures indicated here may vary. As long as idle and WOT
engine speed is set in given range, variance would be ignorable.
Idle adjust screw
C
L mixture needle H mixture needle