Echo SRM-2655SI Instruction manual

SRM-2655SI10-25G-01 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.
ECHO SERVICE MANUAL Ord. 402-24
(Model : SRM-2655) contains lots of
information for servicing this model.
1
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 EMISSION ADJUSTMENT GUIDE ............... 7
2-1 General adjusting rules ..............................7
2-2 Presetting idle adjust screw and idle mixture
needle ........................................................7
2-3 Adjusting carburettor ..................................8
Reference No. 10-25G-01
R E V I S E D : 2 0 0 5 0 2
INDEX ISSUED: 200410

SERVICE INFORMATION SRM-2655SI
2
1 SERVICE INFORMATION
1-1 Specifications
Model SRM-2655SI(L) SRM-2655SI(U)
Dimensions Length* mm(in) 1785 (70.3) 1790 (70.5)
Width mm(in) 360 (14.2) 690 (27.2)
Height mm(in) 350 (13.8) 460 (18.1)
Dry weight** kg(lb) 5.9 (13.0) 6.5 (14.3)
Engine Type KIORITZ, air-cooled, two-stroke, single cylinder
Rotation Anticlockwise as viewed from the output end
Displacement cm3(in3) 25.4 (1.550)
Bore mm(in) 34.0 (1.339)
Stroke mm(in) 28.0 (1.102)
Compression ratio 6.3
Carburettor Type Rotary valve type: Diaphragm, horizontal-draught, with primer (purge bulb)
Model Walbro WYJ-192A
Venturi size-Throttle bore mm(in) 10.5 - 10.5 (0.41 - 0.41)
Ignition Type TCI (Transistor controlled ignition) system
in a single integrated piece
Spark plug BPMR7A
Starter Type - start
Rope diameter x length mm(in) 3.0 x 920 (0.12 x 36.22)
Fuel Type Premixed two-stroke fuel
Mixture ratio 50 : 1 (2 %)
Petrol Minimum 89 octane petrol (RON)
Two-stroke air cooled engine oil ISO-L-EGD (ISO/CD13738), JASO FC
Tank capacity L (U.S.fl.oz.) 0.64 (21.6)
Clutch Type Centrifugal, 2 - shoe pivot
Handle Type Front Crescent loop U-shaped U-shaped
w/cushion grip
Rear Integrated control - - - - - -
grip w/cushion
Drive shaft Type Solid
Diameter - Length mm(in) 7 - 1540 (0.28 - 60.6)
Housing OD -ID mm(in) 25 - 22 (0.98 -0.87)
(Main pipe) Length mm(in) 1500 (59.1)
Gear case Reduction ratio 1.36
Gear tooth Spiral bevel gear
Lubrication Lithium based grease
Cutter Type Nylon line cutter, 3-tooth blade†, Others
Pilot diameter mm(in) 25.4 (1.0)
Fastener type, size mm Left-hand thread nut, M10 x 1.25 pitch
Cutting rotation Anticlockwise as viewed from top
OD: Outer diameter. ID: Inner diameter.
* Without shoulder harness and cutter head. ** With standard cutter head, without shoulder harness.
† Install and use U-shaped handle when operating with steel blade.

SERVICE INFORMATIONSRM-2655SI 3
1-2 Technical data
Engine
Idling speed r/min 2400 - 3000
Operating speed r/min 7000
Wide open throttle speed* r/min 8500 - 10000
Clutch engagement speed r/min 3100 - 3700
Compression pressure MPa (kgf/cm2) (psi) 0.98 (9.8) (138)
Ignition system
Spark plug gap mm(in) 0.6 - 0.7 (0.024 - 0.028)
Minimum secondary voltage at 1000 r/min kV 17
Secondary coil resistance kΩ12 - 13
Pole shoe air gaps mm(in) 0.3 - 0.4 (0.012 - 0.016)
Ignition timing at 1000 r/min °BTDC 25
Carburettor
Main jet #37
Idle adjust screw initial setting turn in** 2 1/2
Idle mixture needle initial setting turn in*** 13 1/2
Test pressure, minimum MPa (kgf/cm2) (psi) 0.05 (0.5) (7.0)
Metering lever height mm(in) 1.5 (0.059) lower than diaphragm seat
BTDC: Before top dead centre.
* With two line nylon line head.
** Set idle adjust screw to contact throttle plate before initial setting.
*** Screw in idle mixture needle from initial thread engagement (at the point that the clicking sound is heard).

SERVICE INFORMATION SRM-2655SI
4
1-3 Torque limits
Descriptions Size kgf•cm N•m in•lbf
Starter Pawl carrier M 8 90 - 120 9 - 12 80 - 100
system Starter case M 4* 14 - 28 1.4 - 2.8 12 - 24
Ignition Magneto rotor (Flywheel) M 8 160 - 200 16 - 20 140 - 175
system Ignition coil M 5 40 - 60 4 - 6 35 - 52
Fan cover M 5 30 - 45 3.0 - 4.5 25 - 40
Spark plug M 14 150 - 170 15 - 17 130 - 150
Fuel Carburettor insulator M 5 50 - 70 5 - 7 45 - 60
system Carburettor M 5 30 - 45 3.0 - 4.5 25 - 40
Fuel tank M 5 30 - 45 3.0 - 4.5 25 - 40
Stand Starter side M 5 20 - 30 2 - 3 17 - 26
Fan cover side M 5 30 - 45 3.0 - 4.5 25 - 40
Clutch Clutch shoe M 6 70 - 110 7 - 11 60 - 95
Engine Crankcase M 5 70 - 110 7 - 11 60 - 95
Cylinder M 5 70 - 110 7 - 11 60 - 95
Top guard M 5* 30 - 45 3.0 - 4.5 25 - 40
Muffler M 5 60 - 100 6 - 10 52 - 85
Muffler cover M 5* 14 - 28 1.4 - 2.8 12 - 24
Others Blade fastening nut LM 10 280 - 320 28 - 32 245 - 280
Regular bolt, nut, M 3 6 - 10 0.6 - 1.0 5 - 9
and screw 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
M 8 110 - 150 11 - 15 95 - 130
M 10 210 - 300 21 - 30 180 - 260
LM: Left hand thread.
* Apply thread locking sealant. (See below)
1-4 Special repairing materials
Material Location Remarks
Thread locking sealant Muffler cover Loctite #242, ThreeBond 1324 or equivalent
Starter case Loctite #222, ThreeBond 1342 or equivalent
Top guard
Grease Gear case
Rewind spring Lithium based grease
Starter drum center hole

SERVICE INFORMATIONSRM-2655SI 5
5K223 5K224
5K225 5K016 5K042
5K182 5K222
5K188
0
5
10
12345678910 11
5K1895K219 5K220
1-5 Service limits
ABCD
EFGH
KLM
Description mm (in)
A Cylinder bore When plating is worn and aluminium can be seen
B Piston outer diameter Min. 33.91 (1.335)
C Piston pin bore Max. 8.030 (0.3161)
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. 9.980 (0.3929)
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. 11.025 (0.4341)
L Crankshaft runout Max. 0.05 (0.002)
M Clutch drum bore Max. 55.5 (2.19)

SERVICE INFORMATION SRM-2655SI
6
a
1.5
1.65
1.3
0.4
20
20
40
40
60
60
80
80
120
120
140
140
160
160
180
180
20
20
100
100
ECHO
Key Part Number Description Used for:
1 897801-33330 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 flywheel
5 897537-12930 Piston stopper Locking crankshaft rotation
6 897563-19830 Metering lever gauge Measuring metering lever height on carburettor
7 897603-23030 PTO shaft puller Removing driven (PTO) shaft
8 897701-06030 Bearing wedge Removing ball bearings on crankshaft
9 897701-14732 Bearing tool Removing and installing crankcase ball bearings
10 897702-30131 Piston pin tool Removing and installing piston pin (Use 8 mm dia. adapter.)
11 897712-04630 2-pin wrench Removing and installing pawl carrier
12 897714-24330 Oil seal tool Installing crankcase oil seals
13 897726-09130 Oil seal tool Removing clutch drum and installing clutch drum ball bearing
14 897719-02830 Piston holder Making piston steady to remove and install piston and rings
15 897800-79931 Spark tester Checking ignition system
16 897803-30132 Pressure tester Checking carburettor and crankcase leakages
17 897826-16131 Pressure rubber plug Plugging intake port to test crankcase and cylinder leakages
18 897827-16131 Pressure plate Plugging intake port to test crankcase and cylinder leakages
19 897835-16131 Pressure connector Checking crankcase and cylinder leakages
20 900600-00012 Washer Installing drive gear
21 91007 Compression gauge Measuring cylinder compression
22 91020 2 way limiter cap tool Removing and installing plug
1-6 Special tools
1
7
16
8
17
a = 3mm
a = 4mm
9
19
11
6
10
13 14 12
21
2
3
54
15
18
20 22

SERVICE INFORMATIONSRM-2655SI 7
2 EMISSION ADJUSTMENT GUIDE
2-1 General adjusting rules
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” 2 stroke oil.
6. Two line nylon line head with properly cut lines must be installed for proper engine loading.
2-2 Presetting idle adjust screw and idle mixture needle
1. Remove the plug from idle mixture needle hole
(A) using 2 way limiter cap tool(B) (91020) as shown.
NOTE : When plug is damaged and left in the hole,
use needle or pin-shaped object to scrape.
2. Turn idle adjust screw (C) anticlockwise until its
tip just touches throttle plate (D). Then turn it in
clockwise 2 1/2 turns.
3. Turn idle mixture needle (E) anticlockwise to fully
come out until clicking sound is heard. Then turn it
clockwise 13 1/2 turns.
(C)
(D) (E)
(A)
(B)

SERVICE INFORMATION SRM-2655SI
8
2-3 Adjusting carburettor
1. Start engine and warm it up well for about 3 - 5 minutes with cycle of 50 seconds WOT (Wide Open
Throttle) and 10 seconds at idling.
2. Adjust idle mixture needle and obtain maximum idle speed with 2.5 mm blade screw driver.
3. Set idle speed 3,500 r/min by turning idle adjust screw.
4. Turn idle mixture needle anticlockwise to reduce idle speed 800 r/min to set idle speed 2,700 r/min.
NOTE : Engine speed must be allowed to stabilize a minimum of 20 seconds after each adjustment of idle
mixture needle to assure accurate tachometer readings.
5. Check WOT engine speed. WOT engine speed should be more than 8,500 r/min.
6. After adjusting carburettor, insert and secure plug
(A) deep in the needle hole per the directive. 2 way
limiter cap tool (B) is useful to insert the plug.
7. Start engine again and make it sure engine runs
in the range of 2,400 to 3,000 r/min at idling and the
range of 8,500 to 10,000 r/min at WOT.Also make it
sure cutting device would not turn at engine idle
speed and suitable acceleration.
(A)
(B)