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Echo shindaiwa CSG-7410ES, Service Manual

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Echo shindaiwa CSG-7410ES Service Manual Download Page 24

FUEL SYSTEM

CSG-7410ES

EC741S

22

4-1 Replacing air filter

IMPORTANT:

 Air filters on CSG-7410ES and EC741S are designed to be maintenancefree for a long pe

-

riod of time. However, in the following cases the main and sub air filters should be replaced.

- When engine output drops remarkably
- After 1 year or 50 hours of operation

NOTE:

 Do not clean the main or sub air filters with compressed air. Otherwise, filters damage may occur.

1. Remove 3 short plug grommets (B) and long 

plug grommet (C) pinching with longnose pliers.

2. Remove 4 pre-coated bolts (D) and cylinder 

cover assembly from the unit.

3. Close choke shutter pulling choke knob (E) to 

avoid dust from entering carburetor.

4. Remove filter case (F) with air filters.

5. Remove main air filter (G) and sub air filter (H) 

from filter case (F).

6. Install new sub air filter (H) into filter case (F).

7. Apply small amount of lithium based grease to 

groove part of new main air filter (G).

8. Install new main air filter (G) into filter case (F).

9. Install filter case (F) with air filters and cylinder 

cover assembly (A) to the unit and tighten 4 pre-

coated bolts (D).

NOTE: 

If the coat is peeled off, replace new one or 

apply ThreeBond #1344 or equivalent. If old thread 

locking sealant is left in threads, correct torque 

may not be secured. In case old thread locking

 

sealant is left, remove it.
10. Install 3 short plug grommets (B) and long plug 

grommet (C) into holes of cylinder cover.

    

A

B

C

D

E

F

F

H

G

lithium

Summary of Contents for shindaiwa CSG-7410ES

Page 1: ...REVISED May 2021 Ref No 401 45 CSG 7410ES ECHO shindaiwa EC741S Copyright C 2020 YAMABIKO Corporation All rights reserved Serial number 30000001 and after Serial number 38000001 and after ...

Page 2: ...nd references We recommend you make use of Operator s Manual and Parts Catalogue together 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 illustra tions and directions in this manual are based on the latest product information available at ...

Page 3: ... 10 Inspecting metering lever height 30 4 11 Inspecting pump diaphragm and inlet screen 31 4 12 Replacing welch plug 31 4 13 Installing carburetor fuel line and tank vent 32 4 14 Adjusting carburetor 35 4 14 1 General adjustment rules 35 4 14 2 Initial setting Throttle adjust screw L mixture needle and H mixture needle 35 4 14 3 Adjusting carburetor 36 5 CLUTCH SYSTEMAND BELT DRIVING SYSTEM 37 5 1...

Page 4: ...nition Type CDI Capacitor discharge ignition system Digital Magneto with stop holding function Spark plug NGK BPMR7A Exhaust Muffler type Spark arrester muffler Starter Type ES Effortless Start S Soft start Rope diameter x length mm in 3 8 x 900 0 15 x 35 4 Fuel Type Mixed two stroke fuel Mixture ratio 50 1 2 Gasoline Minimum 89 octane Two stroke air cooled engine oil ISO L EGD ISO CD13738 JASO FC...

Page 5: ...urn out 3 1 2 3 3 8 L mixture needle turn out 2 Throttle adjust screw turn out 1 2 1 2 Engine warm up Idle WOT Total sec 10 5 120 2 Find idle maximum speed Adjust L mixture needle to maximum idle speed 2 3 Set idle maximum speed w TAS r min 3 700 3 750 4 Set idle speed by turning Lmixture needle CCW When carburetor or diaphragm is brand new 2 800 When carburetor or diaphragm is brand new 2 800 r m...

Page 6: ... 300 28 30 245 262 Clutch drum LM8 150 170 15 17 130 150 Engine Crankcase M5 50 70 5 7 45 60 Cylinder M6 90 120 9 12 80 105 Intake insulator M5 30 45 3 4 5 26 40 Decompression valve M10 120 150 12 15 105 130 Muffler M6 150 170 15 17 130 150 Others Cylinder cover M5 30 60 3 6 26 52 Rear handle Rear handle side M5 40 60 4 6 35 52 Crankcase side M5 30 50 3 5 26 45 Front handle M6 50 70 5 7 45 60 M5 5...

Page 7: ...n and aluminum can be seen B Piston outer diameter Min 50 89 2 004 C Piston pin bore Max 12 030 0 4736 D Piston ring groove Max 1 6 0 063 E Piston ring side clearance Max 0 15 0 006 F Piston pin outer diameter Min 11 98 0 4717 G Piston ring width Min 1 45 0 057 H Piston ring end gap Max 0 6 0 02 K Con rod small end bore Max 15 025 0 5915 L Crankshaft runout Max 0 03 0 0012 N Clutch drum bore Max 7...

Page 8: ... crankcase cylinder leakages 13 897827 16131 Pressure plate Plugging intake port to test crankcase cylinder leakages 14 A131 000150 Pressure connector Testing crankcase and cylinder leakage 15 91149 Pressure Vacuum tester Testing crankcase cylinder leakages 16 897803 30133 Pressure tester Testing carburetor and crankcase leakage 17 91037 Compression gauge Measuring cylinder compression 18 897701 1...

Page 9: ...EM CSG 7410ES EC741S 7 2 STARTER SYSTEM A Starter case G Power spring B Rope guide H Shaft C Starter grip J Cover D Rewind spring K Oil seal E Rope reel L Pawl catcher F Starter rope M Pawl A B C D E F G H J K L M ...

Page 10: ...damage of pawl catcher B may occur 3 Loosen nut D with 10 mm socket wrench E 4 Remove nut D washer F and pawl catcher B 5 Remove 4 screws and cover G NOTE Inspect oilseal of cover G If damaged replace the oilseal with new one Refer to 2 3 Re placing oilseal 6 Remove shaft H and power spring J 7 Pull out starter rope K about 30 cm 12 in and hold rope reel M by hand Loop excess rope in rope reel not...

Page 11: ...ewind spring may un wind suddenly and cause personal injury M N P N A M 2 1 Disassembling starter assembly Continued 9 Remove rope reel M from starter case A slowly to prevent rewind spring from unwinding 10 When removing rewind spring N from rope reel M pinch rewind spring N with pliers P and lift up as shown ...

Page 12: ... turns with starter rope hooked at notch m1 as shown Hold rope reel M to prevent spring from unwinding and pull out starter grip to take the rope slack 5 Pull starter grip several times to check rewind spring tension If starter is not rewinding fully in crease spring tension by rotating rope reel N one more turn clockwise following above step 4 NOTE Lightly hold rope reel M by hand to pre vent rew...

Page 13: ...tighten the nut D by hand until it can not be turned further 14 Pinch pawl catcher B with adjustable wrench C as shown not to rotate pawl catcher B NOTE Do not insert rod shaped tool between the pawls of pawl catcher B to secure it otherwise damage of pawl catcher B may occur 15 Tighten nut D with 10 mm socket wrench E 16 Reinstall starter case A to unit and secure starter case A with 4 pre coated...

Page 14: ...ace damaged or worn parts NOTE When it is hard to loosen bolt install piston stopper X644 000020 E in spark plug hole to stop crankshaft rotation and remove bolt easily 3 Install torsion spring spacer pawl B and bolt A To avoid torsion spring from pinching install these parts without setting the end d of torsion spring on pawl B 4 Using fine wire F or appropriate tool place the end d of torsion sp...

Page 15: ...IGNITION SYSTEM CSG 7410ES EC741S 13 3 IGNITION SYSTEM A Magneto rotor Flywheel E Spark plug cap B Ignition coil F Switch lead C Spark plug G Ignition switch D Spark plug cap coil A B C E G F D ...

Page 16: ...K 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 A if OK S T Not OK A S T Spark test R T Running...

Page 17: ...the needle tips contact Turn out adjuster c2 4 turns to set spark tester gap c2 to 4 mm 0 16 in 4 Pull starter grip several times 5 If spark is steady blue or white at the tester gap ignition system is considered good Go to inspect ing spark plug 6 If no spark exists or spark is intermittent in yellow orange or red continue with further inspec tion 3 3 Inspecting spark plug 1 Remove spark plug to ...

Page 18: ...ctive replace with a new one as follows 7 Remove cap C and replace ignition switch 8 Connect terminal of ignition switch and terminal of switch lead 9 Twist leads counterclockwise and place the leads as shown C 3 4 Replacing spark plug cap and coil 1 Disconnect spark plug cap A from spark plug 2 Apply some oil in spark plug cap A for easy re moval from high tension lead B 3 Pull spark plug cap A a...

Page 19: ...ve 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 2 or 3 is not in the range of 1 5 to 2 5 kΩ replace with a new ignition coil Go to 3 8 Replacing ignition coil Inspecting switch lead 1 Disconnect terminals of switch lead from ignition switch and ignition coil 2 Connect each probe of Ohm...

Page 20: ...hten 2 pre coated bolts A NOTE If the coat is peeled off replace new one or apply ThreeBond 1344 or equivalent If old thread locking sealant is left in threads correct torque may not be secured In case old thread locking sealant is left remove it 8 Connect switch lead terminal B to ignition coil 9 Pass high tension lead D over switch lead as shown NOTE When reinstalling fan cover refer to the note...

Page 21: ...hole by hand to stop crank shaft rotation 4 Remove nut B with 13 mm socket wrench by rotating counterclockwise NOTE Do not use power tool to remove nut B Otherwise piston damage may occur 5 Screw 2 studs E of Puller Y089 000111 into magneto rotor as shown NOTE Screw the studs E into magneto rotor firmly or screw threads may be damaged 6 Put spacer F of Puller Y089 000111 on the end of crankshaft a...

Page 22: ...ng magneto rotor 9 Install woodruff key into key groove as shown 10 Align magneto rotor key groove with woodruff key on crankshaft Install magneto rotor K and fasten nut D clockwise 11 Loosen 2 bolts J and set air gap Refer to 3 8 Setting pole shoe air gaps 12 Retighten 2 bolts J 13 Reassemble all removed parts NOTE When reinstalling fan cover make sure to put high tension lead M in recess N on fa...

Page 23: ... O ring C Fuel tank vent D Fuel tank E Fuel strainer F Fuel line G Pulse line H Pressure line J Carburetor K Carburetor elbow L Intake gasket M Purge bulb N Filter case P Main air filter Q Sub air filter R Cylider cover assembly A B C E D G H J L M N Q P R K F ...

Page 24: ...pulling choke knob E to avoid dust from entering carburetor 4 Remove filter case F with air filters 5 Remove main air filter G and sub air filter H from filter case F 6 Install new sub air filter H into filter case F 7 Apply small amount of lithium based grease to groove part of new main air filter G 8 Install new main air filter G into filter case F 9 Install filter case F with air filters and cy...

Page 25: ...O ring A for cuts or damage and replace with a new one as required 3 Replace fuel cap B if damaged 4 Pull fuel strainer C from fuel tank using a wire hook D Replace if defective or dirty NOTE If cleaner is dirty replace to new one Dirts in strainer can not be cleaned off and may not re cover its filtering function 5 Reinstall fuel cap ...

Page 26: ...E Wrap the ends of longnose pliers with tape or cover with soft pipes D to protect fuel line from damage 7 Apply pressure approx 0 05 MPa 0 5 kgf cm2 7 psi 8 If pressure drops replace fuel line Refer to 4 5 Removing carburetor fuel line and tank vent and 4 13 Installing carburetor fuel line and tank vent 9 Put fuel strainer in fuel tank and fasten fuel cap securely 10 Apply pressure approx 0 01 MP...

Page 27: ...kgf cm2 7 psi 6 If reading does not drop inspect inlet needle valve for sticking or metering lever height is too low 7 If pressure drops at step 3 or if pressure drops below standard figure at step 5 remove carburetor from the unit Refer to 4 5 Removing carburetor fuel line and tank vent 8 Submerge carburetor in suitable clean solvent to locate the leak by applying pressure approx 0 1 M Pa 1 0 kgf...

Page 28: ... from vent line 6 Disconnect fuel lines throttle rod and choke rod from carburetor 7 Remove starter assembly cutter cover assem bly front handle and rear handle referring to the following section Starter assembly 2 1 Disassembling starter as sembly Cutter cover assembly 5 2 Inspecting and re placing belt Rear handle 6 1 Replacing cushions and rear han dle 7 Remove fuel cap and fuel strainer Refer ...

Page 29: ...e If it does not replace tank vent with new one Inspection using Pressure tester 897803 30133 If Pressure vacuum tester 91149 is not available tank vent can be inspected with Pressure tester 897803 30133 as follows 1 Connect tank vent A to Pressure tester 897803 30133 D 2 Apply pressure approx 0 05 MPa 0 5 kgf cm2 7 psi make sure pressure is stable in range of 0 01 0 04 MPa 0 1 0 4 kgf cm2 1 4 5 7...

Page 30: ...lacing air filter and 4 5 Removing carburetor fuel line and tank vent 2 Disconnect pulse line A from carburetor 3 Drop a little 2 stroke oil in the end of pulse line A as shown 4 Remove spark plug and pull starter grip several times Oil should spit back from the hole of pulse line WARNING DANGER Always remove spark plug cap from spark plug before pulling starter rope for main tenance or repairing ...

Page 31: ...s required 3 Inspect metering gasket D and replace if de fective 4 Loosen screw E and remove metering lever F metering lever pin G metering lever spring H and inlet needle valve J 5 Clean fuel passages in carburetor body with compressed air NOTE Before cleaning metering side with com pressed air turn H needle clockwise until lightly seated and remove inlet needle valve Otherwise main nozzle check ...

Page 32: ...ering lever F and metering lever pin G NOTE Insure proper metering lever installation as follows 1 Spring H is seated in its hole at chamber floor 2 Spring H is under dimple of metering lever 3 Metering lever fork is holding inlet needle valve J 9 Inspect metering lever height and adjust the height as required Refer to 4 10 Inspecting me tering lever height F H J G F F 4 10 Inspecting metering lev...

Page 33: ...f engine does not run smoothly even after read justing carburetor and inspecting carburetor parts inspect low speed ports on carburetor as follows 1 Remove metering lever and related parts to pro tect them from damage Refer to 4 9 Inspecting metering chamber and inlet needle valve 2 To remove welch plug B punch the remover tool A through welch plug at low angle and pry it out NOTE Remover tool A a...

Page 34: ...OTE Make sure to pass fuel line A through groove of rear handle as shown 2 Pass fuel line A fuel return line C and vent line G through holes of crankcase as shown 3 Install rear handle to crankcase Refer to 6 1 Replacing cushions and rear handle 4 Connect fuel return line C to long leg of purge bulb 5 Hold vent line G on intake insulator H as shown 6 Connect pressure line L to joint k1 on carbu re...

Page 35: ... return line M to fuel outlet k2 on carburetor 8 Connect choke rod N to choke lever k3 on carburetor as shown 9 Connect throttle rod P to throttle lever k4 on carburetor as shown 10 Connect fuel line A to fuel inlet k5 on carbu retor 11 Connect pulse line Q to joint k6 on carbure tor k2 M k3 N k4 P k5 A k6 Q ...

Page 36: ... shown 14 Secure carburetor elbow R intake gasket S and carburetor K with 2 bolts T 2 spring wash ers U 2 washers V and pre coated bolt W as shown NOTE If the coat is peeled off replace new one or apply ThreeBond 1344 or equivalent If old thread locking sealant is left in threads correct torque may not be secured In case old thread locking sealant is left remove it 15 Install seal X to carburetor ...

Page 37: ...d PET 304 can not indicate correct WOT engine speed When adjusting WOT speed adjust H mixture needle refferring 4 14 2 Initial setting Throttle adjust screw L mixture needle and H mixture needle 4 14 2 Initial setting Throttle adjust screw L mixture needle and H mixture needle Tools required P N 897802 33330 Tachometer PET 1000R P N Y089 000095 Carburetor adjust ment tool Large D shaped tool A 1 T...

Page 38: ... and condition of carburetor 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 Mixed two stroke fuel Premixed alkylate fuel Brand new carburetor or diaphragm Used carburetor Brand new carburetor or diaphragm Used carburetor Idle speed r min 3 300 2 800 6 Stop engine and install cutter blade 7 Rest...

Page 39: ... D E F E 5 1 Adjusting belt tension NOTE Belt tension becomes loose depend on running hours Make sure to adjust the belt tension when it loosens 1 Turn 2 bolts B counterclockwise about 1 turn with 13 mm socket wrench 2 Turn bolt C until aligning position of washer D with mark E on clutch cover as shown 3 Tighten 2 bolts B NOTE Tightening torque is 23 27N m 230 270 kgf cm 200 235 in lbf B A C D E ...

Page 40: ...olt C counterclockwise to loosen belt tension and then remove 2 bolts B and pulley cover A 3 Loosen 2 pre coated bolts P and remove clutch cover N 4 Inspect belt Q for wearing peeling turning cuts and cracking Replace with new one as re quired 5 Remove belt Q and cutter cover assembly R 6 Put new belt Q on pulley on clutch drum S 7 Pass pipe F through groove on clutch cover N F F N ...

Page 41: ...e F to pipe connector on cutter cover assembly as shown 11 Install cutter cover assembly R to cutter arm and then hook belt Q on pulley S 12 Install pulley cover A to cutter arm with slid ing as shown NOTE Make sure the pulley cover is not mis aligned 13 Tighten 2 bolts B with 13 mm socket wrench and then turn 2 bolts B counterclockwise about 1 turn 14 Turn bolt C until aligning position of washer...

Page 42: ...his unit automatically returns to RUN position Engine may start unintentionally 4 Install piston stopper X644 000020 A or clean rope into spark plug hole by hand to stop crank shaft rotation 5 Loosen nut C Left hand thread rotating clock wise with 19 mm socket wrench and remove it NOTE Do not use power tools Otherwise piston damage may occur 6 Remove clutch drum D and collar E from crankshaft 7 In...

Page 43: ... further NOTE If starter assembly is installed untie tem porary knot holding starter grip tied in the first NOTE of 5 1 Inspecting clutch parts While holding starter grip turn clutch assembly counter clockwise until it cannot rotate further 2 Rotate clutch assembly F counterclockwise and tighten with Clutch tool X640 000560 G 3 Install collar E clutch drum D to crank shaft and secure them with nut...

Page 44: ...SG 7410ES EC741S 42 6 HANDLE AND CONTROL SYSTEM A Front handle B Rear handle C Torsion spring D Throttle trigger E Throttle lockout F Rear handle cover G Cushion 5pcs H Cushion J Cushion K Cushion 2pcs G F B A C D E G G G G H J K ...

Page 45: ... stopper bolt C 4 Inspect cushions A for wear and cracks Re place with new one as required 5 Remove 3 cushion caps from cushions A and cushion D 6 Remove 2 hex socket head stopper bolts B and slotted head stopper bolt C 7 Inspect cushions A and cushion D for wear and crack Replace with new one as required 8 Remove rear handle from crankcase 9 Install rear handle to crankcase with passing fuel line...

Page 46: ...car buretor before removing throttle rod F Refer to 4 5 Removing carburetor fuel line and tank vent 3 Set torsion spring E on throttle lever C as shown 4 Install throttle lever C with torsion spring E to rear handle as shown 5 Push throttle lever C upward and then set throttle lockout on rear handle D with hooking tor sion spring E to throttle lockout D as shown 6 Put rear handle cover B on rear h...

Page 47: ...Needle bearing F Piston G Piston pin H Snap ring 2 pcs J Piston ring 2 pcs K Cylinder gasket M Cylinder N Decompressor P Intake pipe A B B C C E F H H G M N R S U V X Y Z Q T Q Band R Intake bellows S Seal T Intake insulator U Muffler gasket V Muffler W Muffler gasket X Exhaust pipe Y Spark arrestor screen Z Exhaust guide ...

Page 48: ...mbly Refer to 5 2 Inspecting and replacing belt 2 Remove cylinder cover assembly Refer to 4 1 Replacing air filter 3 Remove spark plug cap from spark plug WARNING DANGER Ignition switch installed this unit automati cally returns to RUN position Engine can start unintentionally Always remove spark plug cap from spark plug before pulling starter rope for maintenance or repairing otherwise serious pe...

Page 49: ... decompressor remove the depos its or replace with new one as required Refer to 7 5 Inspecting decompressor 3 Reinstall decompressor 4 Remove spark plug and install Compression gauge 91037 A in spark plug hole and tighten by hand Pull starter several times to stabilize reading on compression gauge 5 If pressure is lower than approx 75 of standard compression pressure Refer to 1 2 Technical data in...

Page 50: ...mpressor 5 Remove carburetor Refer to 4 5 Removing carburetor fuel line and tank 6 To seal intake port set Pressure rubber plug 897826 16131 C and Pressure plate 897827 16131 D on intake port Tigten them with M5 bolts E of 10 15 mm 0 4 0 6 in length 7 Connect pulse line F and Pressure vacuum tester 91149 G with suitable joint 8 Apply negative pressure approx 0 03 MPa 0 3 kgf cm2 4 3 psi by the tes...

Page 51: ...ssor A Inspect as follows 1 Remove decompressor A from cylinder with 13mm socket wrench 2 Inspect decompressor A for carbon deposits around the valve a1 and remove the deposits or replace with new one as required NOTE Do not disassemble decompressor 3 Inspect decompressor hole B for accumulating carbon deposits Remove the deposits with screw or suitable tool after removing cylinder from the unit A...

Page 52: ...ylinder D with intake insulator C Inspecting cylinder 1 Inspect cylinder combustion chamber d1 and exhaust port d2 Clean with a plastic or wooden scraper if carbon is found NOTE Do not use metal tools or damage to cylin der wall may result 2 Inspect cylinder wall If plating is worn peeled away scored or exposing cylinder base metal replace with a new one Refer to 7 10 Installing piston and cylinde...

Page 53: ...ove snap ring H from both sides of piston pin NOTE Piston holder 897719 02830 C is recom mended NOTE Do not reuse removed snap rings Make sure to replace with new ones 5 Push piston pin out from piston NOTE If piston pin is tight use Piston pin tool X640 000090 with adapter J stamped 757 6 Inspect needle bearing L and piston pin K and replace if wear or discoloration is noted Refer to 7 10 Install...

Page 54: ...se for damage and discoloration 7 Check ball bearing for smooth rotation If rough replace it them with new one s as follows Removing ball bearing 1 When removing ball bearing on this unit use Boss A Adapter B and Shaft C in Bearing tool 897701 14732 2 When removing ball bearing E from magneto side crankcase half set Shaft C and Adapter B through oil seal and ball bearing E with Boss A as shown 3 T...

Page 55: ...ols 1 Using Bearing tool 897701 14732 and Oil seal tool 897726 21430 1 Use Boss A Adapter F Adapter G and Shaft C in Bearing tool 897701 14732 2 Set ball bearing E with Boss A Adapter F Adapter G and Shaft C as shown 3 Tighten Shaft C with 19 mm wrench to press ball bearing into the crankcase half until flush 4 Check that bearing rotates smoothly 5 Push new oil seal J by maximum 1 0 mm 0 04 in dee...

Page 56: ...h Rod bearing X646 000081 N on crankcase boss as shown 5 Tap Rod bearing N using mallet or press the rod N to put ball bearing in 6 Insert magneto side oil seal and ball bearing using Holder 22169 96410 Rod oil seal 22182 96460 and Rod bearing X646 000050 same as above steps K P N Holder 22169 96410 Holder X643 000020 d1 d2 d1 10mm d2 58mm d3 10mm d4 46mm L 75mm L d4 d3 Flywheel side d5 10mm d6 15...

Page 57: ...al lip from rolling up when inserting crankshaft 5 Insert crankshaft clutch side end into collar oil seal tool R 6 Insert crankshaft magneto side end into mag neto side crankcase half 7 Temporary tighten 6 pre coated bolts S diago nally to loosely assemble crankcase halves NOTE If the bolts S is not long enough prepare longer bolts and tighten with them to get crankcase halves closer Then replace ...

Page 58: ...rotation 9 Tighten 6 bolts to to secure crankcase halves to gether and recheck crankshaft for smooth rotation NOTE If crankshaft does not rotate smoothly loose 6 bolts and tap both ends of crankshaft with plastic mallet several times Then retighten the bolts to secure crankcase 10 Carefully remove excess portion T of crank case gasket with sharp knife ...

Page 59: ...e as shown 3 Insert Piston pin guide B stamped 757 through piston and needle bearing in connecting rod as shown NOTE Piston pin guide B is included in Piston pin tool X640 000090 4 Insert piston pin C in piston pushing out piston pin guide B 5 Install new snap rings E to piston using small flat head screwdriver or appropriated tool F and make sure that they are correctly seated in the grooves D 6 ...

Page 60: ...ankcase NOTE Completely remove old gasket residue on mating surfaces of cylinder and crankcase before setting new gasket 8 Apply 2 stroke oil to piston rings N and internal wall of cylinder 9 Install piston in cylinder with arrow pointing as shown NOTE When installing cylinder it is convenient to use Piston holder 897719 02830 to stabilize pis ton NOTE When installing piston in cylinder do not twi...

Page 61: ...9 8 CUTTING SYSTEM A Pulley cover B Pulley C Bearing case D Drive shaft E Locking knob F Cutter cover G Cutter cover knob H Inner frange J Collar K Snap ring L Outer frange M Pipe N Liquid cock A a b b a c c d d B C F H J K L D E G M N ...

Page 62: ...y from unit 4 Remove bolt D with 19 mm socket wrench and then remove outer frange E 5 Remove snap ring F using small flat head screw and then remove collar G and inner frange H 6 Remove 4 pre coated bolts J and cutter cover plate K NOTE 8 bolts L do not have to be removed 7 Disconnect pipe M from pipe connector on cut ter cover assembly 8 Remove 2 nuts N and bolt P 9 Remove bearing case Q with sli...

Page 63: ...y 13 Remove ring U from cutter cover assembly U T M S 8 2 Replacing pulley drive shaft and ball bearing Removing pulley drive shaft and ball bearing 1 Remove bearing case A and slide plate B from cutter cover assembly Refer to 8 1 Disas sembling cutter cover assembly 2 Remove 2 pre coated bolts C 3 Insert bar tool into pulley G to prevent pulley rotating 4 Remove nut D disk spring E washer F pulle...

Page 64: ...et bearing case A on Holder L 22169 96410 as shown 3 Set ball bearing 6202LLU DDU Q with Rod bearing X646 000050 P on bearing case A 4 Tap Rod bearing P using mallet or press the rod P to put ball bearing Q into bearing case A 5 Insert drive shaft K in ball bearing Q 6 Set ball bearing 6203 R on bearing case A as shown 7 Tap Rod X646 000100 S using mallet or press the rod S to put ball bearing R i...

Page 65: ...t is left in threads correct torque may not be secured In case old thread locking sealant is left remove it 3 Assemble bolt spring E and washers for cutter locking knob as shown 4 Install spring E bolt and washers assembled at step 3 to plate B as shown NOTE Place the longer end of spring E on plate B 5 Set plate for knob F on spring E as shown 6 Set lever G and washer H on plate for knob F and se...

Page 66: ...nut N on cut ter cover as shown 11 Place cutter cover knob O on the nut N and the pipe M and secure the knob O with bolt P 12 Place ring U on cutter cover as shown 13 Place sliding ring V on bearing case as shown 13 Install slide plate A on 2 cushions and secure with 2 nuts Q 14 Secure stopper K with bolt R 15 Set washer S on stopper K and secure with screw T as shown L L M N M P O Q Q A R K T S U...

Page 67: ...MAINTENANCE GUIDE CSG 7410ES EC741S 65 9 MAINTENANCE GUIDE 9 1 Disassembly chart ...

Page 68: ... are extremely noisy Vibration is excessive Cutter blade does not cut well Engine does not stop INSPECTING Starter system Starter rope rope reel Ignition system Sparks Spark plug Spark plug cap coil Ignition switch Ignition coil Pole shoe air gaps Magneto rotor Flywheel 2 2 3 2 3 3 3 4 3 5 3 6 3 7 3 8 3 9 Continued Inspecting first 14 13 12 11 10 09 08 07 06 05 04 03 02 01 14 13 12 11 10 09 08 07 ...

Page 69: ...ine vent 4 3 4 5 4 6 Grommets 4 5 4 13 INSPECTING 14 13 12 11 10 09 08 07 06 05 04 03 02 01 14 13 12 11 10 09 08 07 06 05 04 03 02 01 14 13 12 11 10 09 08 07 06 05 04 03 02 01 REFERENCES Carburetor diaphragms 4 11 Crankcase pulse passage 4 8 Fuel octane freshness purity Cutting system Pulley Bearing Drive shaft Cutter blade Cushion Throttle trigger Throttle rod 8 2 6 2 4 13 6 1 14 13 12 11 10 09 0...

Page 70: ...lug 3 2 3 3 Carbretor 4 4 4 5 4 9 to 4 13 Cooling system 7 1 Muffler and Exhaust port 7 2 Clutch and Clutch drum 5 3 Screws Bolts and Nuts Cushions 6 1 Inspect Clean Repair Replace as required IMPORTANT Service intervals shown above are maximum Actual use and your experience will determine the frequency of required maintenance Retighten the following screws and bolts after first 1 week use and eve...

Page 71: ...MEMORANDUM CSG 7410ES EC741S 69 ...

Page 72: ...MEMORANDUM CSG 7410ES EC741S 70 ...

Page 73: ...MEMORANDUM CSG 7410ES EC741S 71 ...

Page 74: ...Published by YAMABIKO Corp Tokyo Japan 2005 ...

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