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IGNITION SYSTEM

22

CS-2511WES

251Ws

3-9  Inspecting flyweel and woodruff key (Continued)

5. Remove nut (E) by rotating counterclockwise.

NOTE:

  Do  not  use  power  tool  to  remove  nut  (E). 

Otherwise, piston damage may occur.

6.  Remove  starter  pawls.  Then  set  puller 

Y089-

000111

 (F) on flywheel (A) as shown.

7. Tighten two nuts (f1) on the puller alternately to 

remove flywheel (A).

8.  Inspect  woodruff  key  (G)  for  damage  or  shear-
ing. Replace as required.

9. Wipe off oil from taper part of crankshaft and fly

-

wheel before assembling flywheel.

10. Install woodruff key (G) into key groove.

11. Align  the  woodruff  key  with  center  line  of 

crankshaft. Install flywheel and fasten flywheel nut 

clockwise.

12. Reinstall starter pawls (Refer to 

2-4 Replacing 

starter pawl

).

G

G

E

F

A

f1

Summary of Contents for CS-2511WES

Page 1: ...Ref No 401 44 CS 2511WES ECHO shindaiwa 251Ws Serial number 38000001 and after Copyright C 2019 YAMABIKO Corporation All rights reserved...

Page 2: ...guide that describes problems testing remedies and references We recommend you make use of Operator s Manual and Parts Catalogue together with this manual when servicing We are constantly working on...

Page 3: ...eedle valve 36 4 13 Inspecting diaphragm and others 37 4 14 Replacing welch plug 37 4 15 Installing carburetor 38 5 CLUTCH SYSTEM 39 5 1 Inspecting clutch parts 39 5 2 Replacing clutch parts 41 5 3 In...

Page 4: ...to with PI Proportional integral Controller Spark plug NGK CMR7H 10 Exhaust Muffler type Spark arrester muffler with catalyst Starter Type ES Effortless Start S Soft start Rope diameter x length mm in...

Page 5: ...of teeth 8 Pitch in 1 4 1 2 Technical data Engine Compression pressure MPa kgf cm2 psi 1 03 10 5 150 Clutch engagement speed r min 4 400 Ignition system Spark plug gap mm in 0 6 0 7 0 024 0 028 Spark...

Page 6: ...e NOTE Do not stop engine during carburetor adjustment If the engine is stopped restart this procedure from the beginning The carburetor adjustment continues Engine warm up Idle WOT Total sec 5 5 30 2...

Page 7: ...100 150 10 15 90 135 Fuel system Carburetor M5 30 45 3 4 5 26 40 Intake bellows M4 30 45 3 4 5 26 40 Clutch Clutch hub LM8 250 290 25 29 220 255 Engine Crankcase M4 30 45 3 4 5 26 40 Cylinder M4 30 4...

Page 8: ...C Piston pin bore Max 8 035 0 3163 D Piston ring groove Max 1 3 0 051 E Piston ring side clearance Max 0 1 0 004 F Piston pin outer diameter Min 7 98 0 3142 G Piston ring width Min 1 15 0 045 H Piston...

Page 9: ...r assembly 12 91037 Compression gauge Measuring cylinder compression 13 P021 051690 Adapter M10 Measuring cylinder compression for 10mm dia spark plug 14 897826 16131 Pressure rubber plug Plugging int...

Page 10: ...linder 6 When accumulated energy in power spring F overcomes the load from compression pressure in cylinder crankshaft is rotated 7 Power spring F absorbs compression resistance of cylinder and snatch...

Page 11: ...e reel notch d as shown 4 Rotate rope reel D counterclockwise to release tension of rewind spring 5 Remove screw E 6 Remove pawl catcher F and power spring G 7 Remove rope reel D from starter case H s...

Page 12: ...pe through hole of rope reel C 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 throu...

Page 13: ...e B before wind the spring 2 Carefully install rewind spring case assembly C on starter case matching hole c1 with post D Hook a of rewind spring should contact with post E of starter case 3 Wind the...

Page 14: ...Install pawl catcher J engaging hole j with power spring top end hook h2 10 Reinstall screw K on starter post 11 Pull out starter rope inside starter case Rotate rope reel F clockwise 3 turns with st...

Page 15: ...sembly from unit 2 Loosen bolt A and remove pawl B and torsion spring C Replace damaged or worn parts NOTE When it is hard to loosen bolt install clean rope D in spark plug hole E to stop crankshaft r...

Page 16: ...N SYSTEM 14 CS 2511WES 251Ws 3 IGNITION SYSTEM A Ignition switch B Spark plug C Spark plug cap coil D Spark plug cap E Ignition coil F Bolt M4 G Collar H Flywheel J Nut M8 K Woodruff key B C D E H J F...

Page 17: ...OK Not OK S T OK S T Not OK Pole shoe air gaps Replace OK OK Leads connections Not OK OK OK Not OK S T Repair Replace Not OK Remedy Inspect Not OK Woodruff key End Not OK Flywheel magnet Replace R T...

Page 18: ...ignition switch to RUN position Pull start er grip several times 6 If spark is steady blue or white at the tester gap ignition system is considered good 7 If no spark exists or spark is intermittent...

Page 19: ...ect fuel system A 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...

Page 20: ...RUN position tester should indicate infinite resistance 4 When ignition switch is in STOP position tes ter should show that the circuit is in conducting state closed circuit 5 If ignition switch is de...

Page 21: ...er the lead h1 as shown 7 Pass switch leads h1 and h2 through ribs j2 and j3 as shown NOTE Do not hide TAS hole L by the leads h1 and h2 as shown 8 Pass switch leads h1 and h2 through rib J4 and notch...

Page 22: ...collars 8 Remove spark plug cap spark plug cap coil from high tension lead Refer to 3 4 Replacing spark plug cap and coil 9 Install spark plug cap and spark plug cap coil to new ignition coil 10 Appl...

Page 23: ...nition coil After tightening bolts remove Module air gap gauge 91004 B or feeler gauge NOTE When the air gap is too narrow contact with flywheel may result When the air gap is too wide spark is weak 4...

Page 24: ...wheel A as shown 7 Tighten two nuts f1 on the puller alternately to remove flywheel A 8 Inspect woodruff key G for damage or shear ing Replace as required 9 Wipe off oil from taper part of crankshaft...

Page 25: ...nnector F Fuel tank G Fuel tank vent H Fuel strainer J Clip K1 Fuel line in fuel tank K2 Fuel line 3x5x95mm K3 Fuel line L Grommet M Joint L shaped black N Joint black P Purge line L shaped Q Purge bu...

Page 26: ...om flying particles 8 If a large amount of oil sticks on air filter wash away oil with non inflammable solvent detergent NOTE Finding oil on air filter mesh Oil on air filter mesh may close texture ho...

Page 27: ...aged 4 Pull fuel strainer D out from fuel tank using a wire hook E Clean fuel strainer D Replace with new one if defective or heavily soiled 5 Reinstall fuel cap A 4 2 Replacing air cleaner cover latc...

Page 28: ...ers G as shown NOTE Wrap the ends of longnose pliers with tape H or cover with soft pipes to protect fuel line from damage 6 Apply pressure approx 50 kPa 0 5 kgf cm2 7 psi 7 If pressure drops replace...

Page 29: ...m grommet B 3 Connect tank vent A to pressure tester 91149 C 4 Apply pressure approx 50 kPa 0 5 kgf cm2 7 psi Make sure pressure is stable in range of 10 40 kPa 0 1 0 4 kgf cm2 1 4 5 7 psi 5 If it is...

Page 30: ...gently clean tank vent with compressed air or replace with new one NOTE Do not disassemble valves in tank vent as sembly Damage to valves will occur 4 Remove cap C of tank vent and clean sponge D 5 Cu...

Page 31: ...iver to remove purge bulb A from rear handle 3 Disconnect parge line B and fuel return line C from purge bulb A Installing 4 Connect fuel return line C to longer fitting a2 of purge bulb A Connect pur...

Page 32: ...fuel tank G remove fuel cap and remove fuel strainer H and clip J from fuel line G 5 Remove grommet K from the unit together with fuel line G black joint B and tank vent L 6 Remove fuel line G black j...

Page 33: ...side NOTE Push black joint B in grommet E as brim b of joint B touches grommet E 15 Adjust direction of fuel line A and joint B as view R 16 Reinstall fuel return line D through grommet E as shown 17...

Page 34: ...dle Tools Required P N 897802 33330 Tachometer PET 1000R P N Y089 000095 Carburetor adjust ment tool Large D shaped tool A 1 Turn L and H mixture needles clockwise until lightly seated and then turn o...

Page 35: ...wise untill chain stops and then readjust L mixture needle B 6 Set idle engine speed to 4 100 r min by turning Throttle adjust screw D Engine speed should be stable at 4 100 50 r min after Throttle ad...

Page 36: ...g Refer to 4 12 Inspecting inlet needle valve or metering lever height is too low Refer to 4 11 Inspecting metering lever height If pressure remain 50 kPa 0 5 kgf cm2 7 psi or more remove carburetor a...

Page 37: ...e as required 4 11 Inspecting metering lever height 1 Remove carburetor 2 Remove four screws A metering diaphragm cover B metering diaphragm C and gasket D 3 Inspect metering lever E height by Meterin...

Page 38: ...ows Improper assembling of metering lever and spring Dirt between inlet needle valve and valve seat Worn inlet needle valve tip 3 Clean inlet needle valve seat using suitable clean solvent do not use...

Page 39: ...eedle clockwise until lightly seated and remove inlet needle valve Otherwise main nozzle check valve and inlet needle valve spring may be damaged by the compressed air 9 Reassemble removed parts with...

Page 40: ...ever B passing under choke knob K as shown 2 Connect purge line C and joint D of carbure tor and install fuel inlet E of carburetor to fuel line F 3 Pass purge line C through tab G as shown 4 Fasten c...

Page 41: ...rts 1 Loosen nut A and remove sprocket guard B NOTE If starter assembly is installed pull starter rope out about 20 cm 8 in and make a tempo rary knot to prevent starter damage when installing clutch...

Page 42: ...clutch shoes K If their clearances are large re place with new parts 8 Inspect circumuferences k1 and holes k2 hooked springs L for wear Replace with new parts as required 9 Inspect clutch plate F fo...

Page 43: ...ly is installed untie tempo rary knot holding starter grip tied in the first NOTE of 5 1 Inspecting clutch parts While holding starter grip turn clutch assembly counterclockwise untill it cannot rotat...

Page 44: ...cket guard F Collar G Brake connector H Pin J Brake band K Spacer L Compression spring M Brake cover N Bolt M4 C D E G J A K L M 6 1 Replacing brake lever and torsion spring Disassembling 1 Remove sta...

Page 45: ...pring may come out suddenly and cause personal injury 5 Remove torsion spring G from brake lever F 6 Check brake lever F if broken and torsion spring G if deformed or broken Replace with new part s if...

Page 46: ...connector engaging position NOTE Make sure that brake connector A is in engaging position before removing brake cover C otherwise compression spring may jump out 3 Remove bolt D and sprocket guard pl...

Page 47: ...guard as shown Note Make sure notch m of spacer M places as shown 10 Push compression spring N with driver or other suitable tool and install compression spring N in sprocket guard as shown 11 Instal...

Page 48: ...r M Worm gear N Oiler cover F G H A K L K B C E M N D 7 1 Inspecting oil cap and strainer 1 Remove oil cap A 2 Inspect oil cap A for cracks and gasket B for cuts or damage Replace worn or damaged part...

Page 49: ...ain oil in the tank is con sumed 1 Remove starter assembly 2 Push oil tank vent A into oil tank using suitable tool and take out vent A from oil tank 3 Clean oil tank vent A 4 Check that oil tank vent...

Page 50: ...it is recommended to use pipe joint V186 000020 F 6 Tighten oil cap and apply pressure approx 9 8 kPa 0 1kgf cm2 1 4psi 7 Pressure should not drop If the pressure drops leakage may occur at oil line o...

Page 51: ...r A and circular washer B 3 Inspect worm gear A and circular washer B for damage wear or deformation Replace with new part s as required NOTE If worm gear A is dameged inspect gear of auto oiler assem...

Page 52: ...nger gear E can not be rotated go to step 14 7 Prepare ethanol F in container 8 Install new worm gear G to auto oiler B Set clutch drum H on worm gear G engaging sprocket h with two protrusions g of w...

Page 53: ...g K 18 Pull out spring pin J from adjuster needle K with plier 19 Pull out adjuster needle K and spring L from auto oiler body 20 Remove plunger gear E circular washer R spring S and circular washer T...

Page 54: ...o oiler body Release finger from plunger gear E 28 Press adjuster needle K to the bottom orient ing the flat surface k1 as shown This position indicates maximum discharge volume of chain oil 29 Tap ne...

Page 55: ...haft H Needle bearing J Piston pin spacer K Piston pin A D F H K E J L L M N O P R R Q S T U V V W X Y Z L Snap ring M Piston N Piston ring O Cylinder P Cylinder piece Q Gasket Cylinder R Bolt M4 S Ex...

Page 56: ...to stabilize reading on compression gauge 6 If pressure is lower than approx 75 of standard compression pressure Refer to 1 2 Technical data inspect cylinder bore piston and piston ring for wear or d...

Page 57: ...rt and or saw dust D Clean them with wooden or plastic stick or compressed air as re quired 4 Remove ignition coil E if cylinder fins are hard to clean Inspect the clearance of cylinder fins and the c...

Page 58: ...ck F if carbon is found NOTE When cleaning exhaust port always posi tion piston at Top Dead Center TDC to prevent carbon from entering cylinder Do not use metal tool and be careful not to scratch pist...

Page 59: ...or carburetor 3 To seal exhaust port of cylinder cut pressure rubber plug 91041 F off as shown 4 Remove exhaust plate and muffler G with ex haust gasket H Refer to 8 3 Inspecting muffler and exhaust p...

Page 60: ...ankcase seam or oil seal Use soapy water to locate leakage 13 Then apply negative pressure approx 30 kPa 0 3 kgf cm2 4 4 psi by pressure vaccum tester 91149 N and leave for 30 seconds 14 If the readin...

Page 61: ...ly tap both crankshaft ends using plastic mallet B to remove crankcase assembly with crankshaft and piston assembly holding cylinder A 2 Inspect cylinder combustion chamber and clean with a plastic or...

Page 62: ...square end of broken piston ring when cleaning piston ring groove otherwise piston ring groove might be damaged 4 Remove snap rings F from both sides of piston pin 5 Push piston pin G out from piston...

Page 63: ...r adapter K stamped 8 12 Install new snap rings on both end of piston pin Make sure that they are properly seated in snap ring grooves NOTE Always use new snap rings 13 Install piston ring on piston 8...

Page 64: ...Y089 000110 G prepared as follows 1 Drill two 6mm dia holes on puller Y089 000110 G as below 2 Three screws or bolts 91311 04075 H size M4x75mm lengh pitch 0 7mm 3 Three nuts 900500 00004 F size M4 p...

Page 65: ...all bearing C Oil seal B remains in crankcase bore 5 Push out oil seal B with using oil seal tool 897726 09130 E Assembling 6 Set new ball bearing C with shaft A adapter F inner dia 15 mm outer dia 40...

Page 66: ...ake sure to match hole position D of crankcase gasket C and clutch side crankcase half B 4 Reassemble both crankcase halves together en suring that dowel pins b on clutch side crankcase half B are pro...

Page 67: ...nging port b1 of cylinder as shown 3 Set new cylinder gasket C on cylinder B as notch c1 of gasket C aligns pulse hole b2 4 Install piston ring D on piston E ensuring the end gaps of piston ring are p...

Page 68: ...handle B Rear handle C Rear handle lid D Torsion spring E Throttle trigger F Throttle lockout G Throttle rod H Spring holder J Bolt M4 K Bolt M4 L Spring M Bolt M4 N Bolt M4 P Spring D E F A C G H J K...

Page 69: ...part s with new one as required Assembling 5 Insert torsion spring D to throttle rockout E 6 Assemble torsion spring D with throttle rockout E on rear handle lid A as shown 7 Assemble throttle trigger...

Page 70: ...3 Remove front handle D turning the handle as shown 4 Remove bolt E and spring F Assembling 5 Install spring F to rear handle and tighten bolt E NOTE Make sure to set spring F inside projec tion G 6 I...

Page 71: ...lt C and spring cover D 6 Check spring B and replace with new one as required 7 Remove ignition switch and carburetor 8 Remove two plugs F and then remove two bolts G NOTE When removing bolts G always...

Page 72: ...n gine cover Q and then assemble rear handle NOTE Make sure boss R of rear handle insert to hole q2 of enigne cover Q as shown 15 Install spring B and tighten two bolts A NOTE Make sure spring B is in...

Page 73: ...olt M5 M Sprocket guard plate N Stud bolt C D E F A G H J K L M N 10 1 Replacing nut for fixing guide bar Disassembling 1 Pinch hook A with pliers B and remove hook A and nut C from sprocket guard D 2...

Page 74: ...e with new part s as required Assembling 3 Install bevel gear G into sprocket guard H 4 Screw chain tensioner E on tensioner screw D 5 Put bevel gear F on tensioner screw D 6 Install sub assembled ten...

Page 75: ...to remove stud NOTE If it is hard to remove or broken stud is too short for tightening two nuts hold defective stud by vise and turn the chain saw body counterclock wise or use a suitable stud remove...

Page 76: ...is excessive Engine does not stop Oiler does not function Saw chain does not cut well INSPECTING Starter system Starter drum rope Ignition system Sparks Spark plug Spark plug cap coil Ignition switch...

Page 77: ...2 8 1 8 4 1 5 8 6 8 9 1 5 8 7 Fuel tank line vent Purge bulb 4 4 to 4 7 INSPECTING 15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 REFERENCES Carburetor diap...

Page 78: ...ter 4 1 Carburetor 4 9 4 15 Clutch drum 5 1 5 3 3 6 Ignition switch 6 1 Brake lever 8 9 8 11 Crankshaft Spark plug 3 3 3 4 Sprocket guard Throttle control parts 9 1 7 4 Worm gear Flywheel Engine block...

Page 79: ...6 Fuel tank Clean inside 4 4 Muffler and exhaust port Clean 8 3 Starter system Inspect Repair 2 1 to 2 4 Oil tank Clean inside Oil strainer Clean Replace 7 1 Sprocket Inspect Replace 1 5 5 1 Guide ba...

Page 80: ...Published by YAMABIKO Corp Tokyo Japan 1910...

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