Yard Machines LT31 Service Manual

Q Shindaiwa Inc. 1994 1Service ManualShindaiwa Grass Trimmers,Brushcutters and Lawn EdgersContentsSection page1 Model Designation and Identification .

Q Shindaiwa Inc. 199410Section 2 TroubleshootingAll Shindaiwa products are powered by highperformance engines that produce the mosthorsepower from th

Q Shindaiwa Inc. 1994100Pinion Gear and Bearing RemovalSTEP 1. Use a screwdriver to gently spreadthe clamp at the input (drive) end of thegearcase.ST

Q Shindaiwa Inc. 1994 101Assembly is basically the reverse ofdisassembly.STEP 1. Replace the inner bearings (if theywere removed).STEP 2. Hand-fit t

Q Shindaiwa Inc. 1994102Section 12 Lawn EdgersFigure 12.2 Parts unique to Shindaiwa LE-230 andLE-250 lawn edgers.PowerheadThrottle TriggerDebris Shi

Q Shindaiwa Inc. 1994 103Lawn Edgers Section 12NOTE:When in doubt as to interchangeability ofspecific components, consult the appropriateIllustrated

Q Shindaiwa Inc. 1994104Section 13 Appendix SpecificationsSpecifications are subject to change without notice.APPENDIX—SPECIFICATIONSF-18 T-18 F-20 F

Q Shindaiwa Inc. 1994 105Appendix Specifications Section 13F-18 T-18 F-20 F-21 T-20 T-230 C-230 LE-230 T-250 C-250 LE-250IGNITIONIgnition type STCI (

Q Shindaiwa Inc. 1994106Section 13 Appendix SpecificationsSpecifications are subject to change without notice.T-25 C-25 T-27 C-27 C-35 BP-35 B-40 B-4

Q Shindaiwa Inc. 1994 107Appendix Specifications Section 13T-25 C-25 T-27 C-27 C-35 BP-35 B-40 B-45 RC-45IGNITIONIgnition type STCI (all models)Numbe

Q Shindaiwa Inc. 1994108Section 13 Appendix Torque ValuesBolt/ScrewLocation Size F/T-18 F-20 T-20 T/C-230 T/C-250ENGINECrankcase 5 mm 44-60 (50-70)–a

Q Shindaiwa Inc. 1994 109Appendix Torque Values Section 13Bolt/ScrewLocation Size T/C-25 T/C-27 C-35/BP-35/B-40 B-45/RC-45ENGINECrankcase 5 mm 44-60

Q Shindaiwa Inc. 1994 11Troubleshooting Section 2TroubleshootingGuideDoes the engine crank OK?Faulty recoil starter.Fluid in the crankcase.Interna

Q Shindaiwa Inc. 1994110Section 13 Appendix Tolerances and Wear LimitsDimensions: inches (mm) F/T-18 F-20 T-20 T/C-230 T/C-250Piston Diameter use a m

Q Shindaiwa Inc. 1994 111Appendix Tolerances and Wear Limits Section 13Dimensions: inches (mm) T/C-25 T/C-27 C-35/BP-35 B-40 B-45/RC-45Piston Diamete

Q Shindaiwa Inc. 1994112GasolineWhat you need toknow abouttoday’s motorfuels...CAUTION!Under certain conditions, so-called “oxygenated” motor fuelscan

Q Shindaiwa Inc. 1994 113StorageGasoline is a complex blend of many differentcompounds, some of which may degradeduring storage.Old or “stale” gasolin

Q Shindaiwa Inc. 1994114Section 13 Appendix Metric Conversions1 in. = 25.4 mm 1 mm = .03937 in.1 in. = 2.54 cm 1 cm = .3937 in.1 ft. = 30.48 cm 1 cm

Q Shindaiwa Inc. 1994 115Appendix Special Service Tools Section 13Flywheel Puller Assembly20000-96104Piston Pin Puller Assembly (all models)20021-966

Q Shindaiwa Inc. 1994116Notes

Shindaiwa Grass Trimmers,Brushcutters and LawnEdgersSERVICEMANUALSHINDAIWA SERVICE MANUAL

Shindaiwa Incorporated11975 SW Herman RoadP.O. Box 1090Tualatin, OR 97062Phone 503 692-3070FAX 503 692-6696R 1994 Shindaiwa Inc. Form No. 60506 Prin

Q Shindaiwa Inc. 199412Section 2 TroubleshootingTroubleshootingGuideIs the engineoverheating?Operator is overworkingthe machine.Carburetor mixtu

Q Shindaiwa Inc. 1994 13Troubleshooting Section 2TroubleshootingGuidePooracceleration.Clogged air filter.Muffler is clogged.Clogged fuel filter.

Q Shindaiwa Inc. 199414Section 2 TroubleshootingWhenever there is metal-to-metal contactbetween internal moving parts, the enginecan seize. Most engi

Q Shindaiwa Inc. 1994 15Troubleshooting Section 2Overheating (Figure 2.5) Operating an engine with clogged ordamaged cooling fins or with missingcoo

Q Shindaiwa Inc. 199416IMPORTANT!Most seizures are not covered by the war-ranty. Whenever warranty is in question,determine the cause of failure befor

Q Shindaiwa Inc. 1994 17 SEIZURE CHECKLIST PLEASE CHECK THE APPROPRIATE BOX/RESPONSE1. Model__________________________Serial Number___________________

Q Shindaiwa Inc. 199418CRB-15CRB-14IntroductionA carburetor’s only function is to mix air andfuel to accommodate any combination ofengine load and rpm

Q Shindaiwa Inc. 1994 19Carburetors General Information Section 3The following is a list of carburetors used onall Shindaiwa trimmers and brushcutter

Q Shindaiwa Inc. 19942Attention StatementsAdditional attention statements that are notpreceded by the Attention Symbol are:IMPORTANT!A statement prece

Q Shindaiwa Inc. 199420CRB-06Section 3 Troubleshooting CarburetorsTroubleshootingFigure 3.3 Carburetor Troubleshooting GuideMechanical failure of an

Q Shindaiwa Inc. 1994 21Troubleshooting Carburetors Section 3Fuel Tank, Lines,and Filters Test the tank vent for proper operation. Inspect fuel lin

Q Shindaiwa Inc. 199422Section 3 Troubleshooting CarburetorsAll Shindaiwa trimmer/brushcutters use oiledfoam air filter elements. Consult the curren

Q Shindaiwa Inc. 1994 23Troubleshooting Carburetors Section 3Backpressure from a clogged muffler or sparkarrestor can restrict an engine’s high-endpe

Q Shindaiwa Inc. 199424Section 3 Troubleshooting CarburetorsUse Walbro tool p/n 57-11 or equivalent to testthe inlet needle assembly for proper pop-o

Q Shindaiwa Inc. 1994 25TK Carburetors Section 3TK CarburetorsBasicAdjustmentStandard TK Carburetor SettingsModel Slow Air Main AdjustingScrew ScrewF

Q Shindaiwa Inc. 199426Section 3 TK CarburetorsDisassemblingTK CarburetorsFigure 3.11CAUTION!Carburetor components can beeasily misplaced or damagedt

Q Shindaiwa Inc. 1994 27Check valveassemblyTK Carburetors Section 3D. Main JetUnscrew the main jet holder, and remove themain jet.NOTE:The main jet o

Q Shindaiwa Inc. 199428Section 3 TK CarburetorsInspecting TKCarburetorsA. GeneralOutright failure of any carburetor is unusual.Most carburetor proble

Q Shindaiwa Inc. 1994 29D. Metering Valve Assembly Inspect the inlet needle for signs of wearand replace if you discover measurablewear (Figure 3.14)

Q Shindaiwa Inc. 1994 3F-18 Grass TrimmerSHINDAIWA ENGINEMODELSER.NO.X X X X XX X X X X X XACC-20Located on theengineTypicalnameplatelocationTypical

Q Shindaiwa Inc. 199430Section 3 TK CarburetorsH. Choke AssemblyMake sure the choke lever and other chokecomponents are not loose, damaged, ormissing

Q Shindaiwa Inc. 1994 31CARBURETORSTK Carburetors Section 3CRB-28Dimension AUpper surface ofmetering chamberPacking surfaceMeteringleverFigure 3.16

Q Shindaiwa Inc. 199432Section 3 TK CarburetorsReassemblingTK Carburetors(continued)E. Fuel PumpAssemble the fuel pump gaskets and dia-phragms in the

Q Shindaiwa Inc. 1994 33TK Carburetors Section 3CAUTION!Avoid engine overheat damage!Fuels containing alcohol or otheroxygen-bearing compounds can in

Q Shindaiwa Inc. 199434Section 3 Walbro CarburetorsWalbroCarburetorsBasicAdjustment(Figure 3.19)Basic AdjustmentThe Walbro carburetor contains no sep

Q Shindaiwa Inc. 1994 35Walbro Carburetors Section 3DissassemblingWalbroCarburetorsNOTE:Model WYL is typical of current model Walbrocarburetors used

Q Shindaiwa Inc. 199436Section 3 Walbro CarburetorsC. Metering Diaphragm and PumpSTEP 1. Gently peel the metering diaphragmand gasket from the pump

Q Shindaiwa Inc. 1994 37Walbro Carburetors Section 3InspectingWalbroCarburetorsA. GeneralOutright failure of any carburetor is unusual.Most carbureto

Q Shindaiwa Inc. 199438Section 3 Walbro CarburetorsE. Pump Body Inspect the pump body casting for damageor corrosion. Make sure the fuel inlet, airp

Q Shindaiwa Inc. 1994 39Walbro Carburetors Section 3ReassemblingWalbroCarburetorsA. Throttle Valve and Venturi BodySTEP 1. Install the inner idle scr

Q Shindaiwa Inc. 19944Straight-shaftGrass TrimmersT-18 Grass TrimmerT-20 Grass TrimmerT-27 Grass TrimmerSection 1 Model Designation and Indentificati

Q Shindaiwa Inc. 199440Section 3 Walbro CarburetorsInstallatingWalbroCarburetorsSTEP 1. Connect the throttle control wire.STEP 2. Place a new carbu

Q Shindaiwa Inc. 1994 41CARBURETORSWalbro Carburetors Section 3A. High Speed Mixture AdjustmentSTEP 1. Preset the high speed mixturescrew to 1-1/2-

Q Shindaiwa Inc. 199442B. Primer SystemsThe WZ carburetor uses a primer systeminstead of a conventional choke valve. Thesystem draws fuel during rout

Q Shindaiwa Inc. 1994 43Troubleshootingthe WZCarburetorTroubleshooting the primer and air purgesystems usually requires no more thancleaning and servi

Q Shindaiwa Inc. 199444Section 4 Recoil StartersAll Shindaiwa trimmers and brushcutters usea manual starting system that permits anoperator to generat

Q Shindaiwa Inc. 1994 45WARNING!Wear eye and face protectionwhen servicing recoil starters!Coiled starter springs contain storedenergy and may cause i

Q Shindaiwa Inc. 199446Section 4 Recoil StartersDisassemblingthe Recoil(continued)Remove the Starter ReelWARNING!Wear appropriate eye and faceprotecti

Q Shindaiwa Inc. 1994 47Recoil Starters Section 4 Inspect the hub for cracks, fractures, orother damage. Replace if noted. Inspect the pawl (where

Q Shindaiwa Inc. 199448Section 4 Recoil StartersRecoil Spring (Cassette)Carefully install a new Shindaiwa recoilcassette assembly in the starter housi

Q Shindaiwa Inc. 1994 49Recoil Starters Section 4STEP 1. With 6 to 8 inches of starter cord stillprotruding from the reel notch, wind thereel 2 to 3

Q Shindaiwa Inc. 1994 5Model Designation and Indentification Section 1BrushcuttersC-230 BrushcutterC-27 BrushcutterMODEL IDC-250 BrushcutterC-25 Brus

Q Shindaiwa Inc. 199450IGN-26MAGNETSection 5 Ignition SystemsTheory ofOperationFigure 5.1 Acting as a switch, the normally-closed TCI allows the mov

Q Shindaiwa Inc. 1994 51Ignition Systems Section 5IGN-27MAGNETFigure 5.2 Rising primary voltage causes the TCI to abruptly switch off. The magnetic

Q Shindaiwa Inc. 199452Section 5 Ignition SystemsAll Shindaiwa trimmers and brushcutters usea transistorized TCI ignition system poweredby a flywheel

Q Shindaiwa Inc. 1994 53Equipment RequirementsBasic ignition troubleshooting requires anohmmeter, an adjustable-gap spark tester(Figure 5.6), and a sy

Q Shindaiwa Inc. 199454IgnitionTroubleshooting(continued)Section 5 Ignition SystemsIGN-12STEP 1. Test spark with an adjustable gaptester.Install an a

Q Shindaiwa Inc. 1994 55Ignition Systems Section 5STEP 5. Check magneto air gap.(Figure 5.11).Make sure the magneto air gap is set to thespecificatio

Q Shindaiwa Inc. 199456IGN-16STEP 7. Test primary and secondarymagneto windings (two-piece ignition)for continuity. Test primary coil resistance and

Q Shindaiwa Inc. 1994 57STEP 2. Test the spark plug firing voltagebetween the coil high tension lead andthe spark plug terminal. (Figure 5.18).This te

Q Shindaiwa Inc. 199458Section 6 Clutches and FlywheelsAll Shindaiwa trimmers and brushcutters usea centrifugal clutch mounted on the engineflywheel

Q Shindaiwa Inc. 1994 59Clutches and Flywheels Section 6Clutch ShoeOrientationClutch shoe orientation determines whetherinitial clutch engagement occ

Q Shindaiwa Inc. 19946Section 1 Model Designation and IndentificationC-35 BrushcutterB-45 BrushcutterBP-35 BrushcutterRC-45 BrushcutterBrushcuttersMO

Q Shindaiwa Inc. 199460Models With 4-Shoe ClutchSTEP 1. Lock the engine flywheel.STEP 2. Remove the two countersunk screwssecuring the cover plate usi

Q Shindaiwa Inc. 1994 61CLUTCH/FLYWHEELClutch performance and service life aredirectly related to operator habit. Prolonged low-speed operation may c

Q Shindaiwa Inc. 199462Section 6 Clutches and FlywheelsSTEP 1. Remove fan cover and relatedducting as required. Remove the clutchshoe assembly as des

Q Shindaiwa Inc. 1994 63Clutches and Flywheels Section 6 Use a degreasing solvent to clean thecrankshaft taper and the flywheel bore. Carefully ins

Q Shindaiwa Inc. 199464ConstructionSection 7 Cylinders and PistonsAll Shindaiwa trimmer and brushcutterengines combine a two-ring piston running ina

Q Shindaiwa Inc. 1994 65DecarbonizingExamine the exhaust port and combustionchamber for signs of carbon buildup. Use aplastic or wooden scraper to rem

Q Shindaiwa Inc. 199466Before removing the piston (all models), notethe orientation of the arrow cast into the pistoncrown that is pointing towards th

Q Shindaiwa Inc. 1994 67CYLINDERS/PISTONSPiston Pin Removal Method 2Using pin removal tool p/n 72182-96300 andthe appropriate push pin, press the pin

Q Shindaiwa Inc. 199468Section 7 Cylinders and PistonsReassemblyThrust Washers If either thrust washer shows obvious signsof wear or discoloration f

Q Shindaiwa Inc. 1994 69☛Important Tip To aid in properly centeringthe piston pin, preinstall one piston pincirclip opposite the driver tool, then ta

Q Shindaiwa Inc. 1994 7Model Designation and Indentification Section 1Lawn EdgersLE-230 Lawn EdgerLE-250 Lawn EdgerMODEL ID

Q Shindaiwa Inc. 199470Install Cylinder BoltsCoat the cylinder bolt threads with Three-Bond™ Liquid Screw Lock or equivalent, andtighten each bolt onl

Q Shindaiwa Inc. 1994 71Cylinders and Pistons Section 7STEP 1. Install the muffler as described inSection 9.STEP 2. Install carburetor and reconnec

Q Shindaiwa Inc. 199472All Shindaiwa trimmer and brushcuttercrankcases feature diecast aluminum alloyconstruction for longest service life andmaximum

Q Shindaiwa Inc. 1994 73CRK-21Carefully inspect crankcase halves for cracksor other damage.☛ Carefully inspect crankcase matingsurfaces and cylinder b

Q Shindaiwa Inc. 199474Section 8 Engine CrankcaseDirt or accumulateddebris: ReplaceBearingInspectionNormalbearingMissing and/ordamagedcomponents:Repl

Q Shindaiwa Inc. 1994 75 Engine Crankcase Section 8Bearing installation is easiest if the crankcasebearing bore is first expanded slightly with ahea

Q Shindaiwa Inc. 199476Section 8 Engine CrankcaseCrankshaftInspection(Figure 8.16)CRK-20Rod Big EndConnectingRodRod SmallEndWoodruffKey SlotCarefully

Q Shindaiwa Inc. 1994 770102030405060708090CRK-19 Engine Crankcase Section 8 TwistA three-piece crankshaft assembly canbecome twisted from a severe

Q Shindaiwa Inc. 199478Section 8 Engine CrankcaseCrankcase/CrankshaftReassemblyWARNING!Do not allow acetone or paintremover to contact your skin!Alwa

Q Shindaiwa Inc. 1994 79 Engine Crankcase Section 8STEP 4. Install Crankcase “S” Carefully slide crankcase half “S” over thecrankshaft and align it

Q Shindaiwa Inc. 19948CRK-27Section 2 Troubleshooting The 2-Stroke Cycle EngineTheory ofOperation1. IntakeWhen the piston moves up toward the cylin-d

Q Shindaiwa Inc. 199480Current Shindaiwa trimmer and brushcuttermodels feature a unitized sheet-metal mufflerbolted to the engine cylinder through ano

Q Shindaiwa Inc. 1994 81Mufflers Section 9To inspect for carbon buildup at cylinderexhaust ports, remove the muffler from thepowerhead by unscrewing

Q Shindaiwa Inc. 199482Section 9 MufflersMuffler InstallationSTEP 1. Use a scraper to carefully clean themating surfaces on both the muffler andcyli

Q Shindaiwa Inc. 1994 83Mufflers Section 9Assemble the spark arrestor in the reverseorder of dissassembly.Replace all gaskets with new Shindaiwagaske

Q Shindaiwa Inc. 199484Section 10 Mainshafts and Outer TubesAll Shindaiwa straight-shaft trimmers andbrushcutters feature one-piece high-carbonsteel

Q Shindaiwa Inc. 1994 85Mainshafts and Outer Tubes Section 10Mainshaft RemovalSTEP 1. Remove either the powerhead orgearcase from the shaft tube.STE

Q Shindaiwa Inc. 199486Section 10 Mainshafts and Outer TubesSTEP 1. Inspect both mainshaft splines fordamage or wear (Figure 10.3). When indoubt, co

Q Shindaiwa Inc. 1994 87Mainshafts and Outer Tubes Section 10NOTE:Removal of stubborn bushings may requirestriking the driver with a or mallet or dea

Q Shindaiwa Inc. 199488Section 10 Mainshafts and Outer TubesBushing AlignmentBushings may occasionally become mis-aligned or “cocked” during installa

Q Shindaiwa Inc. 1994 89Mainshafts and Outer Tubes Section 10Vibration ComplaintsTrimmer/brushcutter vibration can be difficultto trace by touch alon

Q Shindaiwa Inc. 1994 9Troubleshooting The 2-Stroke Cycle Engine Section 2CRK-26Figure 2.2 The burning mixture expands, forcing thepiston down and r

Q Shindaiwa Inc. 199490Section 10 Mainshafts and Outer TubesSTEP 1. Remove the shaft case housingindex bolt and loosen the clamp bolt(Figure 10.9).S

Q Shindaiwa Inc. 1994 91Mainshafts and Outer Tubes Section 10Flexible ShaftSTEP 1. Unplug the two stop switch wires,disconnect the throttle cable fr

Q Shindaiwa Inc. 199492Section 10 Mainshafts and Outer TubesTroubleshootingVibrationProblemsAll Units Check the outer tube for damage, Inspectthe ma

Q Shindaiwa Inc. 1994 93Mainshafts and Outer Tubes Section 10Diagnosing Vibration ComplaintsIs shaftbent?Safety Clip?(Remove)Bent ArborBolt?Debris

Q Shindaiwa Inc. 199494Section 11 GearcasesAll Shindaiwa gearcases feature hardenedpinion gears supported by four ball bearingsrunning in a cast alum

Q Shindaiwa Inc. 1994 95GRC-17GRC-05Gearcases Section 11NOTE:Models T-18, T-20, T/C-230, T/C-250 and later-series T/C-27 require removing the gearcas

Q Shindaiwa Inc. 199496GRC-15Inner Bearing Removal Use a heat gun to pre-heat the gearcase toapproximately 212°F (100°C), and thenremove the inner be

Q Shindaiwa Inc. 1994 97GRC-16Pinion (drive) Gear and Bearing InstallationSTEP 1. Hand-fit the pinion and bearingassembly into the gearcase input end

Q Shindaiwa Inc. 199498Section 11 GearcasesReassemblyexcept ModelsT/C-250(continued)Inspection Slowly rotate the output shaft by hand, andcheck for

Q Shindaiwa Inc. 1994 99GRC-11GeneralOverall appearance and theory of operation ofthe T/C-250 gearcase is similar to earliermodels, except that the T/