condensed service data

7/16/2019 Condensed Service Data

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ENGINES John Dee

J O H N D E E R E

DEERE & COMPANY400 North Vine

Horicon, WI 53032

CONDENSED SERVICE DATA

ENGINE MODEL TA340A* TB340A*

Bore- (m m) 60 60Inche s 2.362 2.362

Stroke - (mm ) 60 60Inches 2.362 2.362

N o . of Cylinders 2 2Displacem ent-(cc) 339 339

Cubic Inche s 20.6 20 6Cooling Type Axial Fan Fre e AirCarb uretor Model VM B

Number Used 1 i

Ignition Type CDI CDITiming BTDC 22° 22°

M easure dat 6500 rpm 6500 rpmSpark Plug:

Cham pion QN-3 ON-3E le ct ro d e G a p - ( m m ) . . . . . . . 0 .6 35 0 .63 5

Inch 0.025 0.025

Fuel/Oil Ratio 50:1 50:1*Engines manufactured for John Deere by Kawasaki Heavy Industries,

TA440A* TA440B* TC440A*

682.6760

2.3622

436

26.6Axial Fan

VM1

CD I22 °

6000 rpm

QN-3

0.6350.02550:1

Japan .

68

2.6760

2.3622

436

26.6Axial Fan

VM1

CD I18°

6500 rpm

QN-2 or N-20.6350.02550:1

682.6760

2.3622

436

26.6Liquid

VM2

CD I16°

6500 rpm

N-20.6350.02550:1

M AINTE NANCE

SPARK PLUG. The recommendedplug for normal service is given in CON-

DENSED SERVICE DATA table. Adifferent he at rang e or type of plug maybe needed for a particular application.Refer to ENGINE SERVICE FUN-

DAMENTALS section when selecting aspark plug for other than normal usage.

CARBURETOR. Mikuni type VM orB carburetors are used. Refer to the ap-propriate CARBURETOR SERVICE

section for overhaul data. An externalimpulse line from engine crankcase isused to operate fuel pum p. Be sure thereare no vacuum or pressure leaks.

IGNITION SYSTEM. Timingspecifications for individual engines aregiven in CONDENSED SERVICE

DATA tables. All models are equippedwith Capacitor Discharge IgnitionSystem. Because timing is electronic, it

should not change once properly ad-justed. The first step in adjustment.

therefore, would be to check for looseflywheel nut, sheared flywheel key, orloose mounting screws on stator baseplate. On Models TA340A, TA440A,TA440B and TC440A ignition timing isset by aligning mark on stator plate

(1-Fig. JDl) with top of crankcridge (2). For Model TB340A align loest mark (1-Fig. JD2) with top crankcase ridge (2). To adjust remrecoil starter. On some models timcan be adjusted by reaching throughspection holes in flywheel. If these not provided, then remove starter pu

Fig, JD1-S9t ignition timing by aligning markon Btator pitf (1) with crankcas^ ridga (2} and

adjust by looaan lng scnw ($), than rotatingstator Plata forModals TA340A , TA440A , TA440B

and 7C440A.

fig, JD2-Align longaat mark on stator platawith top of crankcaaa ridga (2) to sat timing

Modal TB340A.



ENGINES

Crankcase cap screw tightening se-

TA440A.

Fig. JD4~Crankca9e cap screw tightening se-quence for Model TC440A.

and flywheel retaining nut and lock-washer. Use a suitable puller and with-draw flywheel from crankshaft. Be surenot to lose key in crankshaft keyway.Adjust timing by loosening screws(3-Fig. JDl) and turning stator plate.Reassemble in reverse order of dis-assembly.

LUBRICATION. The engine is lubri-cated by mixing oil with fuel. Use JohnDee re 2-cycle oil or a suitable equ ivalent.Recommended fuel/oil ratio for allengines is 50:1. For models without oilinjection pumps mix fuel and oil thor-oughly in a separate container beforepouring mixture into fuel tank. For coldweather blending, pre-mix the oil with asmall amount of gasoline and shakethoroughly until mixture is liquid, thenblend with remainder of fuel. Do not usekerosene or fuel oil for pre-mixing.

REPAIRS

TIGHTENING TORQUES. Recommended tightening torques are as fol-lows for all models:Crankcase 16 ft.-lbs. (22 N-m )

Cylinder-to-crankcase 16 ft.-lbs. (22 N-m )

Cylinder head 16 ft.-lbs. (22 N -m)

Fig. JD$ —Crankcase cap sc rew tightening se-quence for Modei TA440B.

Flywheel nut 60 ft.-lbs. (81N-m)Spa rk plug 20 ft.-lbs. (27 N- m)Recoil starter

mounting bolts 5 ft.-lbs. (7 N-m )

DISASSEMBLY AND REASSEM-BLY. Remove carburetor, intake mani-fold, muffler, exhaust manifold, drivesheave and recoil starter. On modelswith axial fans, remove cooling shrouds,fan b elt and fan a ssem bly. On liquid cool-ed Model TC440A remove necessarycoolant hoses and related parts. Removestarter cup and flywheel. Remove sparkplug leads and ignition coil. Removeengine wiring as needed, mark locationfor reassembly. Remove stator plate re-taining screws and withdraw plate withleads and grommet from mounting base.Remove and identify cylinder heads, cyl-

inders and pistons, so that parts can bereinstalled in original positions. Removecrankcase securing capscrews andseparate crankcase halves. Refer to ap-propriate section to service components.

To reassemble, reverse disassemblyprocedure. Refer to TIGHTENINGTORQUE section for torque specifica-tions. Refer to IGNITION SYSTEMsection for setting ignition timing. Referto Fig. JD3 for crankcase tightening se-

quence for Models TA340A, TA440Aand TB340A, Fig. JD4 for ModelTC440A and Fig. JD5 for ModelTA440B.

PISTON, RINGS & CYLINDER.Piston crown is marked with an arrowas shown in Fig. JD6 to indicate pistonposition in cylinder. Arrow must point

towards exhaust port. Cylinder assem-bly has a chrome-plated bore and mustbe renewed if out of specification ordamaged. Small deposits of aluminumfrom piston on cylinder wall may beremoved by very careful sanding. Cyl-inder should be inspected for cracking,flaking or any other deterioration of thechrome lining. Also check for appear-ance of underlying base metal throughchrome which indicates excessive wear.Inspect piston for excessive wear ordamage.

Piston pins are full floating with re-

taining rings on each end. Piston ringsare pinned in place as shown in Fig. JD 7.Widest part of ring gap must be facingup when ring is installed as shown inFig. JD7. Piston ring end gap for ModelTA340A should be 0,006-0.014 inch,0.011-0.019 inch for Model TB840A and0.008-0.016 inch for Models TA440A,TA440B and TC440A. Cylinder borediameter should be no more than 2.3669inches for Model TA340A, 2.3675 inchesfor Model TB340A, 2.6818 inches forModels TA440A and TA440B and2.6811 inches for Model TC440A. Ifcylinder bore diameter exceeds specifi-cation, cylinder assembly must berenewed. Piston diameter measured atskirt should be no less than 2.3554 in-ches for Model TA340A, 2,3551 inchesfor Model TB340A, 2.6703 inches forModel TA440A, 2.6693 inches for ModelTA440B and 2.6701 inches for ModelTC440A. If piston diameter is less thanspecification, then piston will need to berenewed.

CRANKSHAFT AND CONNECT-ING ROD ASSEMBLY. The crankshaftand connecting rods are available only

as an assembled unit and should not bedisassembled. Crankshaft main bearings

tOCATlNG MARK

TOWARD OUTPUT

SHAFT

Fig. JD6—instaii piston so that arrow on pistoncrown points towards exhaust port.

Fig. JD7—Piston rings are pinned as shown (ar*

Note that upper ring is instaiied sothat notches in ring ends are up.



ENGINES John Dee

Fig. JDS-End play adiustmant shim for ModalsTA340A, TB340A, TA440A and TA440B.

Fig. JD9-End play adjusmant shim for ModalTC440A.

are a press fit on crankshaft. Rotate allbearings and renew those that are roughor frozen. Outside bearings may berenewed, but inner bearings areavailable only with cranksh aft assembly.Special tools must be used to removeand renew outside bearings in order toprevent damaging crankshaft and com-ponents. Be sure to identify shims andwashers as they are removed, so as to

reinstall in same position as removed.If crankshaft, bearings or crankcase

are renewed, crankshaft must becentered in crankcase by measuring endplay. Crankshaft end play should not ex-ceed 0.030-inch on Models TA340A,

Fig. JDIO-Viaw of a typical Capacitor DIs-charga Ignition systam.

1. Stator plate2. Lighting coil

3. Exciter coil4. Flywheel5. CDI unit

6. Ignition coil

7. Spark plug wire8. Spark plug9. Pulser coiT

Fig, JDii-Explodad vlaw of cooling fan andhousing unit.

1. Cover2. Nu t3. Lockwasher4. Pulley half5. Shims6. Pulley half7. Belt

8. Bearing9. Shim

10. Snap ring11. Housing12. Bearing13. Key14. Fa n

TB340A and TA440A, 0.040-inch onModel TA440B and 0.015-inch onModel TC440A. If end play is out ofspecification, then shim (S-Fig. JD8)will need to be ch anged for all models ex-cept TC440A. For Model TC440A shim(S -F ig . JD9) will need to be changed.

Check crankshaft runout with a dialindicator after reassembly in crankcase.Runout should not exceed 0.002 inch onall models. If runout exceeds specifica-tions, replace crankshaft assembly.

ELECTRICAL SYSTEM. Refer toFig. JDIO for view of a typical CDI unit.The Capacitor Discharge Ignition (CDI)system uses a permanent magnet fly-

wheel (4) to induce voltage into excitercoil (3). The exciter coil then sends cur-ren t to CDI unit (5) where a diode allowsonly DC cur rent to flow into a capacitor.When gate control switch in CDI unitreceives the small current signal frompulser coil (9), it closes and allows thecapacitor to discharge its stored voltageinto the ignition coil (6). The coil then"steps up" voltage enough to fire bothspark plugs simultaneously.

If an engine problem is experiencedcheck fuel system, electrical connec-

Fig. JD12-Vlaw of a typicalracoil startar assambly,

l . N u t2. Lockwasher3. Flat washer4. Plate5. Center spring6. Return spring7. Bushing8. Thrust washer9. Plate

10. Plate11. Reel12. Spring13. Pawl14. Spring15. Handle16. Rope17. Cover

tions, wiring and spark plugs. To CDI ignition system a special testerohmm eter must be used. DO NOT us12 volt test light as it may damage CDI system.

COOLING FAN AND BELT. Btension should be adjusted to allowmore than %-inch deflection midw

between pulleys when depressed wfinger. Belt can be adjusted by addingremoving shims (5- Fi g. JD ll) from tween fan pulley halves. Removshims will tighten belt by allowing purims to move closer together. Tpulley slowly when assembling to kfrom pinching belt in pulley. Remoshims can be stored outside of oupulley half for re-use when a new belinstalled.

To renew belt, remove recoil starfan protector cover and air intake duRemove fan pulley outer half, then w

draw belt and slip it off lower drpulley. Install new belt and adjustoutlined in previous paragraph. Restall parts removed during disassemb

RECOIL STARTER. Refer to ploded view of a typical starter in FJD12 . Caution should be taken when dassembling starter, parts are unspring pressure.

To disassemble starter , remostarter from engine. Remove nut (lockwasher (2) and flat washer (3), thwithdraw retaining plate (4). Remocenter spring (5), return spring (

pawls (13) and pawl springs (1Remove bushing (7), thrust washer and plates (9 and 10) on so equippmodels. Rotate reel (11) to relespring (14) and lift reel (11) out of coassembly (17). Unknot rope (16) remove from reel (11). DO NOT remospring (14) unless replacement needed, as spring will rewind duriremoval.

Inspect and renew all parts that adamaged. Reassemble starter in reveorder of disassembly. Be sure sprinhook in notches during assembly to

sure proper operation of sta rter.

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condensed service data

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