Echo GT-225 Mounting instructions

GT-225, SRM-225
10-21S-01 1
1
INTRODUCTION
We are constantly working on technical im-
provement of our products. For this reason,
technical data, equipment and design are
subject to change without notice. All speci-
fications and directions in this SERVICE
DATA are based on the latest products infor-
mation available at the time of publication.
ECHO SERVICE MANUAL Ord. 402-35
(Model : GT-225, SRM-225) contains lots
of information for servicing this model.
NOTE : Corrected tightening torque of
mufer cover on page 4.
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   
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CONTENTS
page
1 SERVICE INFORMATION.............................. 2
1-1 Specication ................................................... 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 CARBURETOR ADJUSTMENT PROCEDURE......7
2-1 General adjusting rules............................... 7
2-2 Presetting Idle adjust screw, Idle mixture
needle and Hi speed mixture needle..................... 7
2-3 Adjusting carburetor.................................... 8
Reference No. 10-21S-01
REVISED: 201304
ISSUED: 200810

SERVICE INFORMATION
GT-225
SRM-225
2
1 SERVICE INFORMATION
1-1 Specications
Model GT-225 SRM-225
Dimensions* Length mm (in) 1371 (54.0) 1793 (70.6)
Width mm (in) 315 (12.4) 251 (9.9)
Height mm (in) 539 (21.2) 328 (12.9)
Dry weight* kg (lb) 4.6 (10.1) 5.5 (12.1)
Engine Type KIORITZ, air-cooled, two-stroke, single cylinder
Rotation Counterclockwise as viewed from the output end
Displacement cm3 (in3) 21.2 (1.29)
Bore mm (in) 32.2 (1.27)
Stroke mm (in) 26.0 (1.02)
Compression ratio 5.9
Carburetor Type Rotary type : Diaphragm, horizontal-draft, with purge bulb
Model ZAMA RB-K93
Ignition Type CDI (Capacitor discharge ignition) system
Variable Slope Timing (VST) : Slope advance ignition
system combined with electronic speed governor
Spark plug BPM8Y (CANADA : BPMR8Y)
Exhaust Mufer type Spark arrester mufer with catalyst
Starter Type i-30
Rope diameter x length mm (in) 3.0 x 830 (0.12 x 32.7)
Fuel** Type Premixed two-stroke fuel
Mixture ratio 50 : 1 (2%)
Gasoline Minimum 89 octane
Two-stroke engine oil ISO-L-EGD (ISO/CD13738), JASO M345-FC/FD
Tank capacity L (U.S..oz.) 0.44 (14.9)
Clutch Type Centrifugal, 2-shoe pivot
Handle Type Front Loop handle
Rear Integrated control grip Integrated control grip
with throttle lock lever
Drive shaft Type Flexible
Diameter - Length mm 6.0 - 1219 6.15 - 1522
(in) (0.24 - 48.0) (0.24 - 59.9)
Housing OD - ID mm 22.25 - 19.05 25.0 - 22.0
(in) (0.88 - 0.75) (0.98 - 0.87)
Main pipe Length mm (in) 1130 (44.5) 1500 (59.1)
Gear case Reduction ratio --- 1.4
Gear tooth --- Spiral bevel gear
Lubrication Lithium based grease or ECHO LUBETM
Cutter Type Nylon line cutter, 8-tooth blade†, 22-tooth blade†, Others
Pilot diameter for blade mm(in) Not available Option : 20.0 (0.79)
Fastener type, size mm Not available Left-hand thread nut, M10 x 1.25 pitch
Cutting rotation Clockwise as viewed from top Counterclockwise as viewed from top
OD: Outer diameter. ID: Inner diameter. * Without shoulder harness and Nylon line head.
** Refer to Operator’s manual.
† Install blade conversion kit including metal shield when operating with metal blade.

SERVICE INFORMATION
GT-225
SRM-225 3
1-2 Technical data
Model GT-225 SRM-225
Engine
Idling speed rpm 2,900 +/- 400
Wide open throttle speed rpm* 6,900 - 8,100 7,600 - 8,700
Clutch engagement speed rpm 3,850 - 4,100
Compression pressure MPa (kgf/cm2) (psi) 0.66 (6.7) (96)
Ignition system
Spark plug gap mm(in) 0.6 - 0.7 (0.024 - 0.028)
Minimum secondary voltage at 1500 rpm kV 15
Primary coil resistance 320 - 420
Secondary coil resistance k 2.7 - 3.3
Pole shoe air gaps mm(in) 0.30 - 0.40 (0.012 - 0.016)
Ignition timing at 1,000 rpm °BTDC 17
at 3,000 rpm °BTDC 27
at 8,000 rpm °BTDC 42
PET-9000 Parameter #1 29 8
#2 03
Carburetor
Venturi Size mm(in) 9.0 (0.354)
Throttle Bore mm(in) 10.5 (0.413)
Idle adjust screw initial setting turn in** 2 1/2 2 3/8
Idle mixture needle initial setting turn back*** 2 7/8 2 5/8
Hi speed mixture needle initial setting turn back*** 3/4
Test Pressure, minimum MPa (kgf/cm2) (psi) 0.05 (0.5) (7.0)
Metering lever height mm(in) 0.1-0.25 (0.004-0.01) lower than diaphragm seat
BTDC: Before top dead center.
*With Nylon line cutter and shield.
** Set idle speed screw to the point that its tip just contacts throttle plate before initial setting.
***Turn Idle/Hi speed mixture needles counterclockwise from point that needle is lightly seated.

SERVICE INFORMATION
GT-225
SRM-225
4
1-3 Torque limits
Descriptions Size kgfcm Nm inlbf
Starter Starter pawl assembly M 8 80 - 100 8 - 10 70 - 90
system Starter case M 4* 30 - 45 3 - 4.5 25 - 40
Ignition Flywheel M 8 160 - 200 16 - 20 140 - 175
system Ignition coil M 4 35 - 50 3.5 - 5 30 - 44
Fan cover M 4 30 - 45 3 - 4.5 25 - 40
Spark plug M 14 130 - 170 13 - 17 112 - 150
Fuel Carburetor M 5 30 - 45 3 - 4.5 25 - 40
system Intake insulator M 5* 35 - 45 3.5 - 4.5 30 - 40
Fuel tank with stand M 5* 40 - 60 4 - 6 35 - 55
Cylinder cover Fan cover side M 5 25 - 45 2.5 - 4.5 22 - 40
Starter side†M 5 30 - 40 3 - 4 25 - 35
Engine Crankcase M 5 70 - 110 7 - 11 60 - 95
Cylinder M 5 70 - 110 7 - 11 60 - 95
Mufer M 5* 90 - 110 9 - 11 80 - 95
Exhaust guide M 4 15 - 30 1.5 - 3 13 - 25
Mufer cover Fan cover side M 5* 25 - 45 2.5 - 4.5 22 - 40
Starter side†M 5 30 - 40 3 - 4 25 - 35
Other Cutter fastener LM 10 280 - 320 28 - 32 245 - 280
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
M 8 110 -150 11 - 15 95 - 130
LM: Left-hand thread. † Tapping screw
* Apply thread locking sealant. (See below)
** The torque differences among four bolts should not exceed 20 kgfcm (2Nm, 17inlbf) on one cylinder or crankcase
1-4 Special repairing materials
Material Location Remarks
Grease Drive shaft
Gear case
Rewind spring Lithium based grease or ECHO LUBETM
Starter center post
Oil seal inner lips
Thread locking Starter case
sealant Mufer
Mufer cover Loctite #242, ThreeBond #1324 or equivalent
Fuel tank
Intake insulator Loctite #675

SERVICE INFORMATION
GT-225
SRM-225 5
1-5 Service limits
ABCD
EF GH
KLM
Description mm (in)
A Cylinder bore When plating is worn and aluminum can be seen
BPiston outer diameter Min. 32. 10 (1.264)
CPiston pin bore Max. 8. 030 (0.3161)
DPiston ring groove Max. 1. 6 (0.063)
EPiston ring side clearance Max. 0. 1 (0.004)
FPiston pin outer diameter Min. 7. 97 (0.3138)
GPiston ring width Min. 1. 45 (0.057)
HPiston ring end gap Max. 0. 5 (0.02)
KCon-rod small end bore Max. 12. 000 (0.4724)
LCrankshaft runout Max. 0. 03 (0.001)
MClutch drum bore Max. 51. 5 (2.03)

SERVICE INFORMATION
GT-225
SRM-225
6
Key Part Number Description Used for:
1 990511-30017 Tachometer PET-1000 Measuring engine speed
2 363018-00310 Washer Installing crankcase oil seal
3 X605-000050 Torx L wrench Removing and installing bolt
4 897603-23030 PTO shaft puller Removing driven (PTO) shaft
5 897701-06030 Bearing wedge Removing ball bearings on crankshaft
6 897701-14732 Bearing tool Removing and installing crankcase ball bearings
7 897702-30131 Piston pin tool Removing and installing piston pin (Use 8 mm dia. adapter.)
8 91004 Module air gap gauge Adjusting pole shoe air gaps
9 897712-04630 2-pin wrench Removing and installing pawl carrier
10 91020 Limiter plug tool Removing and installing plug
11 897726-09130 Oil seal tool Installing crankcase oil seals
12 990511-30023 Spark tester Checking ignition system
13 897803-30133 Pressure tester Checking carburetor and crankcase leakages
14 91009 Retaining ring pliers Removing and installing retaining ring
15 900100-08008 Bolt Removing magneto rotor (ywheel)
16 433019-12330 Flange nut Removing magneto rotor (ywheel)
17 91037 Compression gauge Measuring cylinder compression
18 900300 Ignition Analyzer : PET-9000 Measuring Ignition timing, Primary/Secondary voltage
1-6 Special tools
1
6
14
7
16
3
8
15
10
5
912
11
1817
24
13