yanmar.pdf

Paragraph 40 YANMAR

B. ScrewsC. Screws1. Axle2. "0" rinff3. Wear sleeve4. Cover5. Outer seal6. Inner seal7. Shims8. Ball bearing (6211)9. "0" ring

10. Retainer11. Gear12. Roller bearing

(NJ207)13. Lockwasher14. Nut15. Gear hotting16. Upper seal

Crc6)C)17. Lower seal

C)18. Bevel gear19. BaU bearing (6209)20. Gasket21. Ck)ver22. lie rod arm23. Snap ring24. Needle bearing

(HMK3530)25. Spindle housing26. Spindle shaft27. Snap ring28. Bevel gear

28A. Washer (30.5x60mm)

29. BaU bearing(6306UU)

30. Gasket31. Cap32. Bushing (35x39x20

mm)33. "0" ring34. Shims35. Steering arm36. Bevel gear37. Ball bearing (6209)38. Shims39. Washer (85x1 mm)40. Snap ring41. "0" ring

Fig. 32-Exploded wiew of outer drive housing used on YM330D models.

Reinstall axle as described in para-graph 5, selecting correct thickness ofthrust washers (56 and 70) which willlimit end play of axle to less than 0.2 mm(0.0079 in.) without binding.

ENGINEAND CLUTCH

FRONT SPLIT

All Models

40. It is necessary to separate thefront axle, radiator and front framefrom tractor for some work includingservice to the timing gears and cover.

Detach ground cable from battery,disconnect headlight wire, disconnecthood holding bracket, then unbolt and

remove hood. Disconnect battery cablefrom starter, remove fan belt guard anddrain cooling system. Disconnect air in-take hose and overflow from expansiontank if installation interferes withseparation. Disconnect upper and lowerradiator hoses. Detach radiator supportrod and steering drag link. Block rearwheels and support tractor under clutchhousing. Insert blocks between sides offront frame to prevent tipping. Onmodels with front wheel drive, unboltdrive shaft cover, loosen clamps thenslide front cover toward rear. Discon-nect spring loaded drive shaft collar, be-ing careful not to lose balls. Rear ofdrive shaft can be similarly detached toremove drive shaft. On all models, sup-port front frame and radiator assembly,unbolt frame side rails from engine, thenroll front end away from tractor.

Reattach front end in reverse of

separation procedure. Tighten screwswhich attach frame side rails to engineto 79-97 N-m (58,27-71.54 ft.-lbs.) tor-que.

Fig. 33—Cross-section showing Instailatlon ofseals (18 and 17). The upper seal (18) is dust seai;

iower seai (17} is oil seal.

14

SHOP MANUAL

CLUTCH SPLIT

All Models

41. To separate tractor betweenengine and clutch housing, observe thefollowing procedure.

Detach ground cable from battery,shut fuel off and disconnect fuel outletline from filter housing. Detach filterhousing from rear of en^ne and movefilter toward rear. On YM135 andYM135D models, detach the batterypositive cable, then remove the battery.On all models, detach hydraulic linesfrom hydraulic pump and throttlelinkage from injection pump. Disconnecttachometer cable, then move cable andhousing back out of the way. Disconnectinterfacing wires from star ter .

temperature sensor, thermostart, oilpressure sensor, alternator and head-lights, then move wires back out of theway. Detach steering drag link from pit-man arm. On four wheel drive models,unbolt drive shaft cover, loosen clamps,then slide front cover toward rear.Disconnect spring loaded drive shaft col-lar, being careful not to lose drive balls.Rear of drive shaft can be similarlydetached to remove drive shaft. On allmodels, block rear wheels, support trac-tor under clutch housing' and attachmovable overhead hoist to engine.Remove screws attaching clutch housingto engine, then carefully roll front oftractor away from clutch housing.

When assembling, observe the follow-ing: Be sure that both return springs areattached to throw out bearing and that

Paragraphs 41-42

front and rear sections of tractor arealigned before attempting to rejoin.Engage pto and turn pto output shaftwhile pushing tractor together. Tightenclutch housing to engine fasteners to theappropriate torque. All 8 mm screwsand nuts should be tightened to 23-30N-m (17-22 ft.-lbs.) torque; 10 mmfasteners should be tightened to 45-58N-m (33-42 ft.-lbs.) torque; 12 mmfasteners should be tighteneci to 79-97N-m (58.3-71.5 ft.-lbs.) torque.

R&R ENGINE WITH CLUTCH

All Models

42. To remove the engine and clutchassembly from tractor, first separatefront axle, frame and radiator as outlin-

89

Fig. 35 - Exploded view of front axle used on yM330D models. Refer to Fig. 32 for legend except the following.

A. Screws 55. Front pivot bracketD. Dipstick (includes bushing

42. Left axle housing 72)43. Roll pin 56. Thrust washer44. Shims (same as (same as 70)

100) 57. Center housing45. Carrier bearinjj: 58. Shims

(6012) 59. Drive pinioni 46. Snap ring (same as 60. Taper roller bear-I 48) ing (32007-same as' 47. Drive axle 63)

48. Snap ring (same as 61. "0" ring46) 62. Pinion housing

49. Gasket 63. Taper roller bear-50. Cover ing (32007-same as51. Gasket 60)

64. Spacer65. "0" ring66. Seal collar67. Oil seal (TC45629)68. Shim69. Nut70. Thrust washer

(sane as 56)71. Rear pivot bracket

(same as 55)72. Bushing (75x80x30

mm)73. Rubber boot74. Snap ring75. Steel ball (11/32-in.)

76. Coupling77. Spline seal78. Washer79. Spring80. Cotter pin81. Drive shaft82. "0" ring83. Gasket84. Drive shaft front

cover85. Clamp86. Boot87. Clamp88. Drive shaft rear

cover

89. Gasket91. Bushing (40x2x22.5

mm)92. Ring gear93. Side gear thrust

washer94. Side gear95. Thrust washer96. Pinions97. Pinion shaft98. Differential hous-

ing99. Right axle housing

100. Shims (same as 44)101. Roll pins

IS

Paragraphs 45-47

ed in paragraph 40, then proceed asfollows:

Shut fuel off and disconnect fuel outletline from filter housing. Detach filterhousing from rear of engine and movefilter toward rear. Detach hydrauliclines from hydraulic pump and throttlelinkage from injection pump. Disconnecttachometer cable, then move cable andhousing back out of the way. Disconnectinterfering wires from star ter ,temperature sensor, thermostart, oilpressure sensor, alternator and head-lights, then move wires back out of theway. Attach movable overhead hoist toengine, remove clutch housing to enginescrews, then carefully move engineaway from clutch housing.

When reassembling, reverse removalprocedure and observe the following: Besure that both springs are attached tothrow out bearing. Cap screws and nutsshould be tightened to correct torques.The 8 mm fasteners should be tightenedto 23-30 N-m (17-22.1 ft.-lbs.) torque; 10mm fasteners should be tightened to45-58 N-m (33.2-42.8 ft.-lbs.) torque and12 mm nuts and screws should be tight-ened to 79-97 N-m (58.3-71.5 ft.-lbs.)torque.

CYLINDER HEAD

All Models

45. REMOVE AND REINSTALL.To remove the cylinder head, refer toparagraph 47 and remove rocker armcover. Disconnect battery, draincoolant, remove fan belt, upper radiatorhose and air intake pipe. On YM135 andYM135D models, remove the alternator.On models so equipped, remove waterpump. On all models, remove fuel leak-off and injection lines. Remove injectionnozzles and cylinder head lubrication oilline. Loosen cylinder head retainingnuts in reverse of order shown in Fig. 40or Fig. 41, then unbolt and removecylinder head. On some two cylindermodels, one of the six retaining nuts islocated in intake passage.

When reinstalling, coat both sides ofhead gasket with "Dow Corning/RTVSilicon Gasket", "Three Bond No. 50" orequivalent, then position gasket on blockwith rolled edge of gasket aroundcylinder bores toward top. The largercooling passages in gasket will be at rear(fiywheel) end of engine. Coat threadswith engine oil and install retainingnuts. Tighten nuts in sequence shown inFig. 40 or Fig. 41. Tighten cylinder headretaining nut to 152.0-156.9 N-m(112-116 ft.-lbs.) torque for YM135,YM135D, YM155 and YM155D models;171.6-181.4 N-m (127-134 ft.-lbs.) tor-que for all other models. Rocker armsupport nuts should be tightened to

Fig. 40-Cylinder head shoutd be tightened insequence shown for all two cyiinder models.

78.5-98.1 N-m (58-72 ft.-lbs.) torque forYM135, YM135D, YM155, YM155DYM240 and YM240D models; 64.7 N-m(48 ft.-lbs.) torque for all other models.Refer to paragraph 47 for adjustingvalve clearance. Install rocker armcover, then adjust decompression con-trols as outlined for models with adjust-ment screws.

46. OVERHAUL. Refer to appropri-ate paragraphs 51, 48, 49 and 50 for ser-vicing rocker arms, valves, seats, guidesand springs. Check cylinder head forfiatness using a straightedge and feelergage. On three cylinder models, headshould be fiat within 0.03 mm whenchecked across retaining stud holeslongitudinally, laterally and diagonally.Maximum warpage limit is 0.1 mm(0.0039 in.). Refer to paragraph 51 forassembly of rocker arms.

VALVE CLEARANCEADJUSTMENT

All Models

47. Recommended valve clearance(tappet gap) is 0.2 mm (0.008 in.) cold forinlet and exhaust valves of YM135,YM135D, YM155 and YM155D; 0.15mm (0.006 in.) for both inlet and exhaustvalves of all other models. Valveclearance should be checked afterassembling cylinder head and approx-imately every 300 hours of operation.

YANMAR

The rocker arm cover for YM195,YM195D, YM240 and YM240D modelsincorporates the inlet air passag:e. On allmodels, disconnect decompression link-age and disconnect or remove interfer-ing hardware, then unbolt and removethe rocker arm cover. Check and adjustvalve clearance when piston is at TDCon compression stroke. TDC mark fornumber 1 (rear) cylinder is marked oncrankshaft pulley as shown in Fig. 47.On two cylinder models the number 2(front) cylinder is 180 degrees (exactlyV2-turn) from the number 1 cylinderposition. On three cylinder models, thefront (number 3) cylinder top deadcenter occurs 240 degrees (exactly2/3-revolution) after the rear (number 1)TDC and the center (number 2) pistonreaches TDC exactly 240 degrees afterthe front. Usually top dead center ismarked for all cylinders and is identifiedby "2T" or "3T"; however, the crankshaftpulley of some models may have onlyone TDC mark which is for rear (number1) cylinder.

Reinstall rocker arm cover by revers-ing removal procedure. Adjust decom-pression lever clearance on YM195,YM195D, YM240, YM240D, YM330 andYM330D models as follows. Remove thesmall covers from rocker arm coverabove each exhaust valve, then turncrankshaft until number 1 (rear)cylinder is at TDC on compressionstroke. Move decompression control todecompression position. Loosen locknut(A-Fig. 48), then turn screw (B) untilclearance is 0 without moving valve.Turn screw (B) in one full turn, thentighten locknut (A). This adjustment willhold valve open approximately 0.8 mm(0.031 in.) when decompression device isengaged. Turn crankshaft to nextcylinder TDC (180 degrees for 2 cylindermodels, 240 degrees fot* front cylinder of3 cylinder models) and adjust decom-pression for next cylinder. On threecylinder models, rotate crankshaft 240degrees and adjust decompression forthe center (number 2) cylinder.

Fig. 4i — Tighten cyiinder head retaining nuts insequence shown for three cyiinder modeis.

Fig. 47-Beginning of infection should occurwhen leading mark (i) is ailgned with notch asshown. When the foHowing mark (T) is aiigned

with notch, piston is at top dead center.

16

SHOP MANUAL Paragraphs 48-51

Fig. 48-View of decompressor lockr)ut (A) and adfusting screw (B). Crosssection drawing showsmethod of operation.

New 41.0 mm(1.6142 in.)

Minimum Limit 36.5 mm(1.4370 in.)

YM195, YM195D, YM330, YM330DFree Length-

New 40.0 mm(1.5748 in.)


YM240, YM240DFree Length-

New 42.5 mm(1.6732 in.)


Maximum deflection limit is 2 degreesor approximately 1.43 mm (0.0563 in.).Be sure to install new guide stem sealswhen reassembling using seal protectorand lubricant to prevent damage duringinstallation.

VALVES AND SEATS

All Models

48. Intake and exhaust valves are not^interchangeable. Valve seats can be re-

onditioned using 15, 45 and 70 degreeFstones. Valve face and seat angle forboth inlet and exhaust is 45 degrees.Recommended seat width is 1.77 mm(0.0697 in.) for YM135, YM135D,YM155 and YM155D models; 2.12 mm(0.0835 in.) for other models. Seats canbe narrowed using 15 and 70 degreestones. Valve is recessed 1.25 mm(0.0492 in.) below surface of head onYM330 and YM330D models and shouldnot be recessed more than 1.85 mm(0.0728 in.). On two cylinder models,valve should not be recessed more than0.5 mm (0.0197 in.). Renew valve ifmargin is not even or is less thanV2 thickness of new valve. Valve stemsand guides should be within limits whichfollow.

YM135, YM135D, YM155, YM155DValve Stem Diameter-

Desired 6.95-7.04 mm(0.2736-0.2772 in.)

Wear Limit 6.9 mm(0.2717 in.)

Valve Guide Diameter-Inlet, Desired 7.0-7.015 mm

(0.2756-0.2762 in.)Wear Limit 7.08 mm

(0.2787 in.)Exhaust, Desired 7.02-7.05 mm

(0.2764-0.2776 in.)Wear Limit 7.08 mm

(0.2787 in.)

Valve Stem to Guide Clearance-Inlet, Desired 0.040-0.065 mm

(0.0016-0.0026 in.)Wear Limit .0.15 mm

(0.0059 in.)Exhaust, Desired 0.045-0.070 mm

(0.0018-0.0028 in.)Wear Limit 0.15 mm

(0.0059 in.)YM195, YM195D, YM240, YM240D,YM330, YM330DValve Stem Diameter-

Desired 7.96-7.97 mm(0.3134-0.3138 in.)


Valve Guide Diameter, Inlet & Exhaust-Desired 8.010-8.025 mm

(0.3154-0.3159 in.)Wear Limit 8.08 mm

(0.3181 in.)Valve Stem to Guide Clearance-

Desired 0.045-0.070 mm(0.0018-0.0028 in.)


Install new valve stem seals whenevervalves are serviced.

VALVE SPRINGS

All Models

49. Valve springs are interchangeablefor inlet and exhaust valves. Renew spr-ings which are distorted, heat discoloredor fail to meet test specifications whichfollow:

YM135, YM135D, YM155, YM155DFree Length-

VALVE GUIDES

All Models

50. Inlet and exhaust valve guides arenot interchangeable. Inlet valve guide isusually marked by a second (identifying)groove and passage end of exhaustguide is counterbored. Stem to guideclearance should be 0.040-0.065 mm(0.0016-0.0026 in.) for inlet valves ofYM135, YM135D, YM155 and YM155Dmodels. Exhaust guides for YM135,YM135D, YM155, YM155D and for bothinlet and exhaust valves of all othermodels should have 0.045-0.070 mm(0.0018-0.0028 in.) stem to valve guideclearance. Valve and/or guide should berenewed if clearance exceeds 0.15 mm(0.0059 in.). New guides should be press-ed into cylinder head until the groove inguide is just above upper surface ofcylinder head.

ROCKER ARMSAND PUSH RODS

All Models

51. Rocker arms can be removedafter removing rocker arm cover.Rocker arms for one cylinder are locatedon the shafts of a support stand which isretained to cylinder head by one studnut. The diameter of the rocker armshaft should be 13.98-14.00 mm(0.5504-0.5512 in.) with wear limit of13.90 mm (0.5472 in.) for YM135,YM135D, YM155 and YM155D models,16.98-17.00 mm (0.6685-0.6693 in.) withwear limit of 16.90 mm (0.6654 in.) for

17

Paragraphs 52-54 YANMAR

FRONT

other models. Bushing pressed intorocker arm should have inside diameterof 14.024-14.034 mm (0.5521-0.5525 in.)with wear limit of 14.10 mm (0.5551 in.)for YM135, YM135D, YM155 andYM155D models, 17.016-17.034 mm(0.6699-0.6706 in.) with wear limit of17.15 mm (0.6752 in.) for other models.Clearance between bushing and shaftshould not exceed 0.15 mm (0.0059 in.)for any model.

On two cylinder models, two differentrocker arms are used; however, oncewear pattern is established, rocker armsshould not be relocated to another shaft.On three cylinder models, rocker armswith different offsets are used as shownin Fig. 51.

Push rods should be straight and canbe checked by rolling on a fiat plate.Length of new push rod is 165.2 mm (6.5in.) for YM135, YM135D, YM155 andYM155D models; 197 mm (7.75 in.) forother models.

On all models, loosen locknuts andturn adjustment screws out toward topbefore installing rocker arms and sup-port. Be sure that dowel pin correctlyengages hole in support. Tighten rockerarm support retaining nuts to 78.45-98.07 N-m (58-72 ft.-lbs.) torque forYM135, YM135D, YM155 and YM155Dmodels; 64.72 N-m (48 ft.-lbs.) torquefor other models.

CAM FOLLOWERS

All Models

52. All models are equipped withmushroom type cam followers which can

TIMING MARKS

Fig. 51 — View of rocker armsused on three cyiindermodels. Notice that bothrocker arms for front (No. 3)cyiinder are different thanarms used for other

cylinders.

only be removed from below afterremoving camshaft as outlined in para-graph 60 or 61 and oil pan. Check sur-face of cam follower which contactscamshaft and renew followers if worn.Also check camshaft carefully if followershows wear and renew camshaft if chip-ped, broken, scored or otherwise worn.Cam follower OD is 10.976-10.994 mm(0.4321-0.4328 in.). Clearance betweencam follower and block bore should be0.006-0.035 mm (0.0002-0.0014 in.) withmaximum limit of 0.10 mm (0.0039 in.).

VALVE TIMING

All Models

53. Refer to paragraph 54 or 55 forremoval of timing gear cover. Valves areproperly timed when timing marks arealigned as shown in Fig. 52. Marks alignevery second revolution of crankshaft.

TIMING GEAR COVERYM135, YM135D, YM155, YM155DModels

54. To remove the timing gear cover,first split front of tractor as described in

7Fig. 54 —Cross-section of timing gear covershowing governor of yM135, rMtd5D, YM155and YM155D models. Refer to Fig. 54A for

iegend.

paragraph 40. Remove fan belt, fan,crankshaft pulley and breather/gover-nor control cover. Disconnecttachometer cable from housing andlinkage from governor control. Refer toparagraph 87 and remove injectionpump. Unbolt and remove the timinggear cover.

Be sure that all of old gasket is remov-ed, then coat new gasket with sealerbefore installation. Be sure that sleeve(17-Fig. 54A) correctly engagesweights (20) and be careful not to bendor otherwise damage governor controllinkage when installing cover. Refer toparagraph 101 for governor ad-justments if correct adjustment is questioned or if any adjustment point hasbeen disturbed. Tighten retainingiscrews to 22.56-29.42 N-m (16.6-21.7ft.-lbs.) torque. Install crankshaft pulleyafter lubricating seal surface andtighten retaining screw to 117.7-147.1N-m (87-108 ft.-lbs.) torque. Refer toparagraph 87 for installation of fuel

4

Fig. 52— View of timing marks on camshaft andcrankshaft gears.

Fig. 54AExpioded view oftiming gear cover, governorand related parts used onYM135, YM135D, YM155 and

YM155D modeis.

1. Governor spring2. Washer3. Spring body4. Washer5. Locknut6. High speed stop screw7. Damper spring8. Locknut9. Lock cap nut

10. Pivot shaft11. Steel ball (9/32-inch)12. External speed control

lever13. "O"ring14. Shaft15. Internal speed control lever16. Follower lever17. Governor sleeve18. Governor lever19. Pins20. Weights21. Bracket22. Guide sleeve23. Injection pump24. Hydraulic pump and drive

gear

18

SHOP MANUAL

16 3 18

Fig. SS-Cross-section of governor assembly for YM330 and YM330D models. Refer to Fig. SSA forlegend. Models YMISS, YM19SD, YM240 and YM240D are similar.

pump and paragraph 40 for installingfront axle and frame.

YM195, YM195D, YM240,YM240D, YM330 and YM330DModels

55. To remove the timing gear cover,first split front of tractor as described inparagraph 40. Remove fan belt, fan,hydraulic pump and crankshaft pulley.Disconnect tachometer drive cable fromhousing. Remove injection pumpchamber cover plate, then disconnectgovernor spring (1 - Fig. 55), remove pin(2) and detach governor link from rack.Be careful not to deform spring whendetaching spring from speed controllever. Unbolt and remove timing gearcover.

Be sure that all of old gasket is remov-ed, then coat new gasket with sealerbefore installation. Be sure that sleeve

1. Governor spring2. Clip3. Adjusting nut4. Adjusting nuts5. Locknut

6. High speed stop screw7. Torque spring and shaft

assy.8. Locknut9. Lock cap nut

(17-Fig. 55A) correctly engagesweights (20) and be careful not to bendor otherwise damage governor link (16)when installing cover. Refer to para-graph 103 for governor adjustments ifcorrect adjustment is questioned or ifany adjustment point (3,4,5,6 or 7) hasbeen disturbed. Stud nuts attaching tim-ing gear cover should be tightened to24.52-26.58 N-m (16.6-19.5 ft.-lbs.) tor-que. Install crankshaft pulley afterlubricating seal surface and tighten re-taining screw to 63.74 N*m (47 ft.-lbs.)torque. Tighten stud nuts retaininghydraulic pump to 68.65 N • m (50ft.-lbs.) torque.

TIMING GEARS

YM135, YM135D, YM155 andYM155D Models

56. Refer to paragraph 54 forremoval of timing gear cover. Backlash

Fig. 554 - Exploded view oftiming gear cover and gover-nor assembly for yM330 andYM330D models. Twocyiinder yMT95, YM195D,YM240 and YM240D models

are similar.10. Attaching screw11. Spring tab12. External speed control

lever13. "0" ring14. Shaft15. Internal speed control lever16. Governor link17. Governor sleeve18. Governor lever19. Pins20. Weights21. Bracket22. Pivot support23. Injection pump24. Spacer

Paragraphs 55-60

between camshaft and crankshaft gearsshould be 0.08-0.16 mm (0.0031-0.0063in.) with wear limit of 0.3 mm (0.0118in.). Crankshaft gear can be pulled fromcrankshaft using threaded holes in gearand a suitable puller. Align keyway withkey and timing marks (Fig. 52), then usethreaded hole in crankshaft to push gearonto crankshaft.

Refer to paragraph 60 to remove cam-shaft if camshaft gear is to be removed.


57. Refer to paragraph 55 forremoval of timing gear cover. Backlashbetween camshaft and crankshaft gearsshould be 0.08-0.16 mm (0.0031-0.0063in.) with wear limit of 0.3 mm (0.0118in.). Backlash between camshaft gearand hydraulic pump drive gear and bet-ween crankshaft gear and engine oilpump drive gear should also be less than0.3 mm (0.0118 in.).

The crankshaft gear can be pulledfrom crankshaft using threaded holes ingear and a suitable puller. Align keywaywith key and timing marks (Fig. 52),then use threaded end of crankshaft andnut to push gear onto crankshaft.

Refer to paragraph 61 to remove cam-shaft if camshaft gear is to be removed.

CAMSHAFT

YM135, YM135D, YM155 andYM155D Models

60. To remove the camshaft, firstremove the cylinder head as outlined inparagraph 45, then refer to paragraph54 and remove the timing gear cover.Use magnetic holding tools to raise camfollowers away from camshaft. Removecamshaft bearing retaining screw (Fig.59), then pull camshaft and gear for-ward out of cylinder block. Camshaftgear and front bearing can be pressedfrom camshaft after removing nut andgovernor weight assembly. Measurecamshaft lobes and journals against thevalues which follow.Rear (Flywheel) Journal -

Diameter, New 29.939-29.960 mm(1.1787-1.1795 in.)


Clearance in Bushing,Desired 0.04-0.081 mm

(0.0016-0,0032 in.)Wear Limit 0.15 mm

(0.0059 in.)Center Journal -



(0.0020-0.0039 in.)

19

Paragraphs 61-66 YANMAR


Inlet and Exhaust Lobe-Height New 35.0 mm

(1.3780 in,)Fuel Pump Lobe-

Height New 45.0 mm(1.7717 in.)

When supported at ends in lathecenters, runout measured at centerbearing should be less than 0.05 mm(0.0020 in.). Press front bearing on cam-shaft, position key in slot, then presscamshaft gear onto camshaft. Installfuel pump cam lobes with marks towardfront. Both fuel pump cam lobes areidentical, but must engage key in cam-shaft. Tighten retaining nut securely.

The cam followers can be withdrawnfrom bores after removing camshaft andoil pan. Sepcifications for cam followersare listed in paragraph 52.

Locate camshaft in cylinder blockafter cam followers are positioned at topof travel in block bores. Install bearingretainer screw through hole in web ofcamshaft gear. Refer to paragraph 87for installing fuel injection pump,paragraph 54 for installing timing gearcover and paragraph 45 for installingcylinder head.


61. To remove camshaft, first removethe cylinder head as outlined in para-graph 45, then refer to paragraph 55 toremove the timing gear cover and para-graph 89 to remove the fuel injectionpump. Use magnetic holding tools toraise cam followers away from cam-shaft. Remove bearing retaining screw(Fig. 59), then pull camshaft and gearforward out of cylinder block. Camshaftgear and front bearing can be pressedfrom camshaft after removing nut (lefthand thread) and governor weight.Measure camshaft lobes and journalsagainst the values which follow.Rear (Flywheel) Journal -




(0.0020-0.0039 in.)Wear Limit 0.15 mm

(0.0059 in.)Center Journal -




(0.0020-0.0039 in.)


Inlet and Exhaust Lobe,Desired 38.63 mm

(1.5209 in.)Wear Limit 38.13 mm

(1.5012 in.)Fuel Pump Lobe,

Desired 34.9 mm(1.3740 in.)


When supported at ends in lathecenters, runout measured at centerbearing should be less than 0.05 mm(0.0020 in.). Press front bearing on cam-shaft, position key in slot, then presscamshaft gear on camshaft.

The cam followers can be withdrawnfrom bores after removing camshaft andoil pan. Specifications for cam followersare listed in paragraph 52.

Locate camshaft in cylinder blockafter cam followers are positioned at topof travel in block bores. Install bearingretainer screw through hole in web ofcamshaft gear. Refer to paragraph 89for installing fuel injection pump,paragraph 55 for installing timing gearcover and paragraph 45 for installingcylinder head.

ROD AND PISTON UNITS

All Models

65. Connecting rod and piston unitsare removed from above after removingcylinder head as outlined in paragraph45 and removing oil pan. Remove con-necting rod cap and push piston and rodassembly up out of cylinder block.

When assembling, space ring end gapsat 90 degree intervals from each otherand 45 degrees from piston pin center-line. Coat pistons, liners and ring com-pressor with clean engine oil. Identi-fication marks on connecting rodsshould be toward rear (flywheel) end ofengine. Tighten connecting rod cap re-taining screws to 44.13-49.03 N-m(33-36 ft.-lbs.) for YM135, YM135D,YM155, YM155D, YM240 and YM240D

Fig. 59— View of governor weights and bracketsassembled on cam gear typical of many modeis.The camshaft of ail models is retained by screw

identified by arrow.

models, 63.74 N-m (47 ft.-lbs.) torquefor YM195, YM195D, YM330 andYM330D models.

PISTONS, SLEEVES AND RINGS

All Models

66. Measure stand out of cylinderliners (sleeves) above the cylinder block.A puller should be used to pull wet typecylinder liners from block bores. Be surethat manufacturers marks on all ringsare toward top when assembling rings topistons. Check clearances against thevalues which follow:

YM135, YM135DLiner Stand Out 0.05-0.13 mm

(0.0020-0.0051 in.)Cylinder Liner ID-

New 73.000-73.030 mm(2.8740-2.8752 in.)


Piston Skirt to Cylinder Liner-Clearance, New 0.108-0.173 mm

(0.0043-0.0068 in.)Wear Limit 0.3 mm

(0.0113 in.)Piston Skirt Diameter at Bottom ofSkirt/Right Angles to Piston Pin-

New 72.891-72.922 mm(2.8697-2.8709 in.)


Ring End Gap-All Rings, Desired 0.2-0.4 mm

(0.0079-0.0157 in.)Wear Limit 1.5 mm

(0.0591 in.)Ring to Groove Side Clearance -

Desired-Top 0.050-0.085 mm(0.0020-0.0033 in.)

2nd,3rd & Bottom.. 0.020-0.055 mm(0.0008-0.0022 in.)

Wear Limit-Top,2nd & 3rd . . . 0.2 mm(0.0079 in.)

Bottom 0.15 mm(0.0059 in.)



New 75.000-75.030 mm(2.9528-2.9539 in.)



(0.0043-0.0068 in.)Wear Limit 0.3 mm


New 74.891-74.922 mm(2.9485-2.9497 in.)


20

SHOP MANUAL Paragraph 70


(0.0079-0.0157 in.)Wear Limit 1.5 mm

(0.0591 in.)Ring to Groove Side Clearance-

Desired-Top 0.050-0.085 mm(0.0020-0.0033 in.)

2nd,3rd & Bottom.. 0.020-0.055 mm(0.0008-0.0022 in.)

Wear Limit-Top,2nd & 3rd 0.2mm(0.0079 in.)

Bottom 0.15 mm(0.0059 in.)



New 84.000-84.035 mm(3.3071-3.3085 in.)



(0.0030-0.0056 in.)Wear Limit 0.3 mm


New 83.893-83.923 mm(3.3029-3.3041 in.)



(0.0118-0.0197 in.)Wear Limit 1.5 mm


Desired-Top 0.055-0.095 mm(0.0022-0.0037 in.)

2nd,3rd & Bottom.. 0.020-0.055 mm(0.0008-0.0022 in.)

Wear Limit-Top .0.3 mm(0.0118 in.)

2nd & 3rd. 0.2 mm(0.0078 in.)

Bottom 0.15 mm(0.0059 in.)

YM240, YM240DLiner Stand Out 0.07-0.10 mh.


New 90.000-90.035 mm(3.5433-3.5447 in.)



(0.0043-0.0068 in.)Wear Limit 0.3 mm

(0.0118 in.)'Piston Skirt Diameter at Bottom ofSkirt/Right Angles to Piston Pin-

New 89.862-89.892 mm(3.5379-3.5391 in.)


Ring End Gap-All Rings, Desired .. .0.3-0.5 mm

(0.0118-0.0197 in,)Wear Limit 1.5 mm


Desired-Top 0.080-0.115 mm(0.0031-0.0045 in.)

2nd,3rd & Bottom. . 0.020-0.055 mm(0.0008-0.0022 in.)

Wear Limit-Top 0.3 mm(0.0118 in.)

2nd&3rd 0.2 mm(0.0079 in.)

Bottom 0.15 mm(0.0059 in.)



New 84.000-84.035 mm(3.3071-3,3085 in,)

Wear Limit 84,2 mm(3.3150 in.)

Piston Skirt to Cylinder Liner-Clearance, New 0.077-0,142 mm

(0.0030-0,0056 in.)Wear Limit 0.3 mm


New 83.893-83.923 mm(3.3029-3.3041 in.)



(0,0118-0.0197 in.)Wear Limit 1.5 mm


Desired-Top 0,055-0.095 mm(0,0022-0.0037 in.)

2nd,3rd & Bottom.. 0.020-0.055 mm(0.0008-0.0022 in.)

Wear Limit-Top 0.3 mm(0.0118 in.)

2nd,3rd & Bottom 0.25 mm(0.0098 in.)

The top ring is chromium plated, thesecond and third rings have a taperedface and the bottom (oil control) ring hasbeveled edges for better scraping action.It is important to install all piston ringswith marked side of ring toward top(closed end) of piston.

If cylinder sleeves are removed, besure to clean grooves thoroughly and in-stall new "0" rings in grooves. Coat linerwith waterproof paint and insert sleeveinto block before paint dries. If linerstand out is too high, check to be sureblock and sleeve are clean and free ofrust, scale or burrs.

PISTON PIN

All Models

70. Piston pin is a transition fit inpiston bores with slight interference fitor small amount of clearance. Piston pinshould have recommended clearance inconnecting rod small end bushing. Toremove piston pin, remove retainingrings from piston, heat piston to 80-100degrees C, then press piston pins frompiston bores. Refer to the followingspecification data:

YM135, YM135D, YM155, YM155DPiston Pin

Diameter 29.989-30.000 mm(0.9053-0.9058 in.)

Clearance In Rod Small End Bushing-Desired 0.025-0,049 mm

(0.0010-0.0019 in.)Wear Limit 0.11 mm

(0.0043 in.)Diameter of Pin Bushing In Connecting

Rod-Desired 23.025-23,038 mm

(0.9065-0.9070 in.)Pin Fit In Piston Bores -

Desired, Interference toClearance -0,004 to +0.008 mm

(-0.0002 to +0.0003 in.)

YM195, YM195D, YM240, YM240DPiston Pin

Diameter 29.989-30,000 mm(1,1807-1,1811 in,)

Clearance In Rod Small End Bushing-Desired 0.025-0.049 mm

(0.0010-0.0019 in.)Wear Limit 0.15 mm

(0.0059 in,)Diameter of Pin Bushing In Connecting

Rod-Desired 30.025-30.038 mm

(1.1821-1.1826 in.)Pin Fit In Piston Bores-

Desired, Interference toClearance -0,005 to +0.019 mm

(-0,0002 to +0.0007 in.)

YM330, YM330DPiston Pin Diameter . . . 29.95-30.00 mm

(1.1791-1.1811 in.)Clearance In Rod Small End Bushing-

Desired 0,025-0.049 mm(0.0010-0,0019 in.)

Wear Limit 0.15 mm(0,0059 in.)

Diameter of Pin Bushing In ConnectingRod-

Desired 30,025-30.038 mm(1,1821-1.1826 in.)


Pin Fit In Piston Bores-Desired, Interference to

Clearance -0.005 to +0.019 mm(-0.0002 to +0.0007 in.)

21

Paragraph 71

Side Clearance of Rod Between PistonBosses -

Desired 0.2-0.5 mm(0.0079-0.0197 in.)


Align both holes in bushing with holesin connecting rod. When assemblingpistons, pins and connecting rods,observe the following:

Install one piston pin retaining snapring in one groove of each piston, thenheat pistons to 80-100 degrees C(176-212 degrees F). Coat piston pinsand rod bushings with clean engine oiland install cool pin through rod bushingand heated piston. Be sure to install se-cond retaining ring in piston groove.After cooling, connecting rod shouldmove smoothly on piston pin.

CONNECTING RODSAND BEARINGS

All Models

71. Connecting rod crankpin bearing

inserts are available in standard size and0.25 mm undersize; however, be surethat undersize inserts are obtainedbefore machining crankshaft crankpins.Rod bearing inserts can be installedfrom below after removing oil pan.Refer to the following specification data:

YM135, YM135D, YM155, YM155DPiston Pin Bushing ID-

Desired 23.025-23.038 mm(0.9065-0.9070 in.)


Crankpin Journal Diameter-Desired 46.950-46.964 mm

(1.8484-1.8490 in.)Wear Limit 46.920 mm

(1.8472 in.)Connecting Rod Bearing to CrankpinClearance -

Desired 0.036-0.095 mm(0.0014-0.0037 in.)


Rod Side Play on Crankpin -Desired 0.15-0.35 mm

(0.0059-0.0138 in.)

YANMAR

Rod Bolt Torque 44.13-49.03 N-m(33-36 ft.-lbs.)

YM195, YM195D, YM240, YM240D,YM330, YM330DPiston Pin Bushing ID-

Desired 30.025-30.038 mm(1.1821-1.1826 in.)


Crankpin Journal Diameter-Desired 53.950-53.964 mm

(2.1240-2.1246 in,)Wear Limit 53.91 mm

(2.1224 in.)Connecting Rod Bearing to CrankpinClearance -

Desired 0.036-0,095 mm(0.0014-0.0037 in.)


Rod Side Play on Crankpin -Desired 0.15-0.35 mm

(0.0059-0.0138)Wear Limit 0.50 mm

(0.0197 in.)Rod Bolt Torque 63.74 N-m

(47 ft.-lbs.)

13

1941

40

Fig. 60 - Exploded view of cylinder block and related parts used on YM135, YM135D, YM155 and YM155D models. Refer to Fig. 54A for governor assembly. ^16. Oil filter

1. Screw 10. Crankshaft 19. Bearings and spacer 26. Camshaft 40. Governor and hydraulic ̂2! Crankshaft pulley 11. Rear main bearing 21. Nut 27. Cam follower pump drive gear3. Front oil seal 12. Rear bearing and seal 22. Governor weights 29. Oil pressure sender 41. Drive shaft5 Crankshaft gear housing 23. Camshaft gear 37. Tachometer drive 42. Adapter6 Front main bearing 13. Rear oil seal 24. Retaining screw 38. Injection pump cam lobes9' Thrust bearings 15. Oil pump 25. Camshaft front bearing 39. Spacer

43. Hydraulic pump44. Shim

22

SHOP MANUAL Paragraph 72

CRANKSHAFT ANDMAIN BEARINGS

Two Cylinder Models

72. The crankshaft of two cylindernnodels is supported in two main bear-ings and crankshaft end thrust is takenby a thrust washer (9-Fig. 60 or Fig.61) located at each end of the crank-shaft. To remove the crankshaft and/ormain bearings from all models, proceedas follows:

Separate the front axle, frame andradiator as outlined in paragraph 40,then refer to paragraph 42 to completeremoval of engine. Refer to paragraph45 to remove the cylinder head and toparagraph 54 to remove the timing gearcover. Refer to paragraph 65 to removethe rod and piston units and toparagraph 131 for removing the clutchand flywheel. Pull crankshaft gear fromcrankshaft and remove the oil pick-uptube. Turn the engine so that weightrests on front face of cylinder block andrear end is up. Weight of crankshaftshould be vertical against front ofengine.

Unbolt and remove rear main bearingand seal housing, being careful not todamage the rear thrust bearing. With-draw crankshaft from cylinder block.Use care to prevent damage to all parts

^including the front thrust bearing which

will be free to fall as the crankshaft islifted out of front main bearing. Inspectmain bearings and crankshaft using thefollowing specification data.

YM135, YM135D, YM155, YM155DCrankshaft Main Journal (Both)

Diameter -New 64.950-64.964 mm

(2.5571-2.5576 in.)Wear Limit 64.91 mm

(2.5555 in.)Main Bearing (Both) Diameter-

New 65.00-65.049 mm(2.5591-2.5610 in.)


Main Journal to Bearing Clearance -New 0.036-0.099 mm

(0.0014-0.0039 in.)Wear Limit 0.2 mm

(0.0079 in.)

YM195, YM195D, YM240, YM240DCrankshaft Main Journal (Both)

Diameter-New 69.950-69.964 mm

(2.7539-2.7545 in.)Wear Limit 69.90 mm

(2.7520 in.)Main Bearing (Both) Diameter-

New 70.00-70.06 mm(2.7559-2.7583 in.)


Main Journal to Bearing Clearance-New 0.036-0.099 mm

(0.0014-0.0039 in.)Wear Limit 0.2 mm

(0.0079 in.)The front main bearing (6-Fig. 60 or

Fig. 61) is pressed into cylinder blockand the rear main bearing (11) is pressedinto rear housing on all models. Be sureto align oil holes in bearings withpassages in block and housing whenpressing new bearings into position.Rear seal (13) should be pressed intorear bore of housing with lip towardfront (inside).

The thrust washers which limit crank-shaft end play should be 2.9-3.0 mm(0.1142-0.1181 in.) thick with wear limitof 2.75 mm (0.1083 in.). Crankshaft endplay should be 0.1-0.2 mm(0.0039-0.0079 in.) with maximum limitof 0.4 mm (0.0157 in.). Be sure that allbearings and seals are lubricated withengine oil and stand cylinder block onfront face so that crankshaft can be in-serted from above. Position the frontthrust washer in block recess with oilchannels toward crankshaft and lugengaging notch in block. Lower thecrankshaft into block. Use grease tostick thrust washer into rear bearingand seal housing. Be sure that lubrica-tion grooves are toward crankshaft andlug on thrust washer engages notch inhousing. Install rear bearing and seal

44

14

1. Nut9. Thrust beariniars

44. Shim

Fig. 61 - Partially exploded view of timing gears, camshaft and crankshaft for YM195, YM195D, YM240 and YM240D models. Refer to Fig, $2 for legend ex-cept the following.

23

Paragraph 73

housing with thrust washer carefully us-ing proper thickness of gasket (44). Thethickness of gasket (44) should beselected to adjust crankshaft end playwithin limits of 0.1-0.2 mm(0,0039-0.0079 in.). Screws attachingrear bearing housing should be tighten-ed to 37.27 N-m (27.5 ft.-lbs.) torque.Make sure that crankshaft rotates freelyafter assembly. Complete assembly byreversing disassembly procedure. Fly-wheel retaining screws should betightened to 63.74-68.65 N-m (47-50ft.-lbs.) torque for YM135, YM135D,YM155 and YM155D models. Flywheelretaining nut used on YM195, YM195D,YM240 and YM240D models should betightened to 372.65-411.88 N-m(275-304 ft.-lbs.) torque.

Three Cylinder Models.

73. The crankshaft is supported infour main bearings and end thrust istaken by the flanged main bearing(9-Fig. 62) located at the third (fromfront) position. To remove the crank-shaft and/or main bearings from allmodels, proceed as follows:

Separate the front axle, frame andradiator as outlined in paragraph 40,then refer to paragraph 42 to completeremoval of engine. Refer to paragraph45 to remove the cylinder head and toparagraph 55 for removing the timinggear cover. Refer to paragraph 65 toremove the rod and piston units and toparagraph 131 or 134 for removing theclutch and flywheel. Pull crankshaftgear (5-Fig. 62) from crankshaft andremove the oil pick-up tube (30), Turnthe engine so that weight rests on frontface of cylinder block and rear end is up.Weight of crankshaft should be verticalagainst front of engine.

Unbolt and remove the rear mainbearing and seal housing (12). Jackscrew (threaded) holes are provided inrear bearing housing to facilitateremoval. Attach hoist to rear of crank-shaft and raise shaft slightly to removeweight from center main bearings.Remove set bolts from both center mainbearing housings, then carefully liftcrankshaft (10) and center main bearinghousings (8) from cylinder block.Remove bolts from center main bearinghousings, then separate and remove

YANMAR

housings and inserts from crankshaft.Inspect main bearings and crankshaftusing the following specifications:

YM330, YM330DCrankshaft Main Journal-

Diameter, New-Front &Center 69,95-69,96 mm

(2.7539-2,7543 in.)Diameter, New-Rear 89.95-89.96 mm

(3.5413-3.5417 in.)Wear Limit-Front & Center 69.92 mm

(2.7528 in.)Wear Limit-Rear 89,92 mm

(3.5402 in,)Main Bearing Diameters-

New-Front & Center 70,00-70,04 mm(2.7559-2,7575 in,)

New-Rear 90.00-90.04 mm(3.5433-3.5449 in.)

Wear Limit-Front & Center 70.12 mm(2,7606 in.)

Wear Limit-Rear 90.15 mm(3.5492 in.)

Main Journal to Bearing Clearance -New-Front & Center 0.036-0,099 mm

(0.0014-0.0039 in.)New-Rear 0,066-0,132 mm

(0.0026-0.0052 in.)

28

2221

37

1Fig. 62-Partiaiiy expioded vievn of timing gears, camshaft and cranicshaft for YM330 and YM330D models, inset is oii pressure relief valve.

1. Screw2. Crankshaft pulley3. Front oil seal4. Oil deflector5. Crankshaft gear6. Front main bearing7. Front indermediate main

bearing

8. Center main bearinghousings.

9. Thrust bearing10. Crankshaft11. Rear main bearing12. Rear main bearing and E

housing13. Rear oil seal

14. Flywheel15. Oil pump16. Oil filter17. Hydraulic pump drive

coupling18. Pump drive gear19. Bearings and spacer20. Snap ring21. Nut

22. Governor weight23. Camshaft gear24. Retaining screw25. Camshaft front bearing26. Camshaft27. Cam follower28. Rocker arms29. Oil pre.ssure sender

30. Oil pick up t31. Nut32. Housing33. Relief valve34. Spring35. Shims36. Retainer37. Tachometer

Ubi

halt

drive

24

SHOP MANUAL Paragraphs 75-80

Wear Limit-Front & Center 0.15 mm(0.0059 in.)

Wear Limit-Rear 0.20 mm(0.0079 in.)

The front main bearing (6) is pressedinto cylinder block and the rear mainbearing (11) is pressed into rear housing.Be sure to align oil holes in bearingswith passages in block and housing whenpressing new bearings into position.Rear seal (13) should be pressed intorear bore of housing with lip towardfront (inside).

Assemble intermediate (center) mainbearing housings (8) with arrows oncasting halves aligned with "F" marktoward FLYWHEEL end of engine. Besure that tangs of bearing inserts (7 and9) correctly engage notches in housings.Intermediate main bearing (9) withthrust surfaces should be installedclosest to flywheel end (third main bear-ing from front). Tighten screws holdingintermediate bearing halves together to63.74-68.65 N-m (47-51 ft.-lbs.) torque.Crankshaft end play should be 0.09-0.19mm (0.0035-0.0075 in.). Lubricate allbearings and seals with engine oil andstand cylinder block on front face so thatcrankshaft can be inserted from above.Lower the crankshaft with intermediatemain bearings into cylinder block, align-ing holes in intermediate housings withbolt and lubricating holes in block. In-stall both screws retaining intermediatehousings loosely, then tighten the re-taining screw for rearmost (numberthree) intermediate main bearing to78.45 N-m (58 ft.-lbs.) torque. Aftertightening the retaining screw for thethrust bearing, tighten retaining screwfor the other intermediate bearing hous-ing to 78.45 N-m (58 ft.-lbs.) torque. In-stall the rear bearing and seal housing,tightening the retaining screws to 37.27N'm (27.5 ft.-lbs.) torque. Make surethat crankshaft rotates freely and thatend play is within limits of 0.09-0.19 mm(0.0035-0.0075 in.) after all retainingscrews are properly tightened. Flywheelretaining screws should be tightened to63.74-68.65 N-m (47-51 ft.-lbs.) torque.Complete assembly by reversingdisassembly procedure.

CRANKSHAFT REAROIL SEAL

All Models

75. The lip type crankshaft rear oilseal (13-Fig. 60, Fig. 61 or Fig. 62) iscontained in rear bearing and seal hous-ing. Seal can be renewed after splittingtractor between engine and clutch hous-ing as outlined in paragraph 41, thenremoving clutch and flywheel.

Lip of rear seal should be toward front(inside housing). On two cylinder

models, thickness of gasket (44-Fig. 60or Fig. 61) controls crankshaft end play.Use grease to stick rear thrust washeron to rear housing while assembling. Besure grooved side of thrust washer istoward crankshaft thrust surface andthat lug on thrust washer engages notchin rear housing. Crankshaft end playshould be 0.1-0.2 mm (0.0039-0.0079 in.).Insufficient end play after assembling isusually caused by incorrect alignment ofthrust washer.

On YM135, YM135D, YM155 andYM155D models, tighten rear housingretaining screws to 19.61-24.52 N*m(14.5-18.1 ft.-lbs.) torque. On all othermodels, the rear housing retainingscrews should be tightened to29.42-39.23 N-m (22-29 ft.-lbs.) torque.The flywheel retaining nut used onYM195, YM195D, YM240 and YM240Dshould be tightened to 372.65-411.88N-m (275-304 ft.-lbs.) torque. Theflywheel retaining screws used on othermodels, should be tightened to63.74-68.65 N-m (47-51 ft.-lbs.) torque.

CRANKSHAFT FRONT OIL SEAL

All Models

76. The lip type crankshaft front oilseal (3-Fig. 60, Fig. 61 or Fig. 62) canbe removed after removing crankshaftpulley (2). Lip of seal should be towardinside. Correct installation of seal ismuch easier if front axle, radiator andfront frame is separated from front ofengine as described in paragraph 40.

FLYWHEEL

All Models

78. The flywheel is positively locatedon crankshaft by a key on YM195,YM195D, YM240 and YM240D models;or by a dowel pin on all other models. Onall models, make sure that mating sur-faces of flywheel and crankshaft areclean and free of dirt, rust and burrs.The flywheel retaining nut or screwsshould be tightened to correct torque.The flywheel retaining nut used onYM195, YM195D, YM240 and YM240Dmodels should be tightened to372.65-411.88 N-m (275-304 ft.-lbs.) tor-que; the flywheel retaining screws usedon other models should be tightened to63.74-68.65 N-m (47-51 ft.-lbs.) torque.

Pilot bearing is bushing type for all ex-cept YM330 and YM330D models withlive pto which uses a ball type pilot bear-ing. Pilot bushing inside diameter is14.966-14.984 mm (0.5892-0.5899 in.)for all models with bushing and shaftoutside diameter should be14.935-14.953 mm (0.5880-0.5887 in.).Clearance between shaft and pilot

bushing should be 0.3 mm (0.0118 in.).Old bushing can be pulled from borewith blind hole puller. Install newbushing flush with recess in shaft orflywheel.

Pilot bearing is ball type on YM330and YM330D models with live pto. Ballbearing should be renewed if anyroughness is noted.

Clutch to flywheel retaining screwsshould be tightened to 22.56-29.42 N-m(17-22 ft.-lbs.) torque.

OIL PUMP AND RELIEF VALVE

All Models

80. The rotor type oil pump is attach-ed to the rear face of engine block anddriven by rear of camshaft on YM135,YM135D, YM155 and YM155D modelsas shown at (15-Fig. 60). On othermodels, the oil pump is attached to thefront face of engine block and is geardriven from crankshaft gear as shown at(15-Fig. 61 or Fig. 62).

The pump can be removed fromYM135, YM135D, YM155 and YM155Dmodels after separating between engineand clutch housing, then removing theflywheel. The oil pump can be removedfrom other models after removing thetiming gear housing as outlined in para-graph 55.

Pump rotor end play in housing can bemeasured with straightedge acrosspump body and inserting feeler gagebetween straightedge and pump rotor.End play should be 0.06-0.10 mm(0.0024-0.0039 in.) and should not ex-ceed 0.3 mm (0.0051 in.). Pump outerrotor to body bore clearance should be0.050-0.105 mm (0.0020-0.0041 in.) withwear limit of 0.15 mm (0.0059 in.). Pumpinner rotor tip to outer lobe clearanceshould be 0.050-0.105 mm (0.0020-0.0041 in.) with wear limit of 0.15 mm(0.0059 in.).

On all models, oil pressure relief valveis located in housing (32-Fig. 60, Fig.61 or Fig. 62) for oil filter. Correct oilpressure is 147-245 kPa (21.34-35.56 psi)for YM135, YM135D, YM155 andYM155D models; 245-343 kPa (35.56-49.78 psi) for all other models. Additionor removal of one shim (35-Fig. 62) willchange oil pressure approximately 18kPa (2.6 psi).

DIESEL FUELSYSTEM

Yanmar PFR2K two plunger fuel in-jection pump is used on all two cylindermodels and Yanmar PFR3K threeplunger fuel injection pump is used on

25

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