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- 44 - 

7

79

77

78

0,15 mm

 4 kgm (Nm 39,2)

 1,75 ÷ 2,25 mm

Engine assembly

Checking injector protrusion

Before  mounting  the  heads  to  the  cylinders  fit  the  injectors 

into  their  housings  and,  after  having  secured  them  temporarily, 

check the protrusion of the nozzles from the head faces (fig.77). 

Protrusion 

should be:

Cylinder heads

For  checking  and  overhaul  of  the  cylinder  heads  refer  to  page 

19.

Fit the push rods and oil sealing O-rings on the cover pipes and 

proceed to install the cylinder heads with the relative gaskets on 

the facing surfaces. 

 Important 

• 

Make sure that the oil seal rings are correctly seated in the heads 

to avoid the risk of oil leaks.

Align  the  heads  using  a  metal  bar  or  the  exhaust  manifold 

(fig.78). 

Following  a  cross  pattern  tighten  the  head  nuts  (fig.78)  in 

increments of 1 kgm until you reach the value:

This value is adjusted by inserting copper washers between the 

injectors and the injector supporting faces on the heads (fig. 77).

Valve clearance

The clearance between valves and rockers with the engine cold 

(fig.79) is:

This  clearance  is  to  be  adjusted  with  the  pistons  at  their 

respective TDC compression positions.

intake/exhaust

KD425-2 Workshop Manual_cod. ED0053031750_

1° ed

_ rev.

 

00

Summary of Contents for KD425-2

Page 1: ...KD 425 2 WORKSHOP MANUAL...

Page 2: ...art at the time of the marketing ofengine However development on the engines is continuous Therefore the information within this manual is subject to change without notice and without obligation KOHL...

Page 3: ...ne name plate The complete and updated list of authorized Kohler service centers can be found on our web site www kohlerengines com www lombardinigroup it dealer locator Pls contact Service Centers fo...

Page 4: ...ctors 22 Extracting the oil pressure indicator plug 23 Extraction of crankshaft gear 23 Extraction of flywheel side main bearing 22 Extraction of the camshaft gear 23 Removing the flywheel 22 4 CHECKS...

Page 5: ...pipes 47 Main bearings flywheel side 40 Oil filter 47 Oil pump 42 Pistons 43 Preparing the crankcase 39 Pulley and flywheel 42 Timing cover 42 Valve clearance 44 8 ENGINE TESTING 48 Speed adjustment 4...

Page 6: ...6 KD425 2 Workshop Manual_cod ED0053031750_1 ed_ rev 00...

Page 7: ...7 KD425 2 Workshop Manual_cod ED0053031750_1 ed_ rev 00...

Page 8: ...recoil rope starting is not permitted even in emergencies Check that the machine is stable so that there is no risk of it overturning Get to know the engine speed adjustment and machine stop operation...

Page 9: ...removal of the rotary guards disconnect and insulate the positive cable of the battery so as to prevent accidental short circuits and activation of the starter motor Check the belt tension only when...

Page 10: ...r combine oils with different characteristics Discontinue use of the engine if any irregularities arise particularly in the case of unusual vibrations Do not tamper with any devices to alter the level...

Page 11: ...fuel only in approved containers in well ventilated unoccupied buildings Do not fill the fuel tank while the engine is hot or running since spilled fuel could ignite if it comes in contact with hot pa...

Page 12: ...Danger of entangling and cutting Presence of explosive fuel Danger of fire or explosion Presence of steam and pressurized coolant Danger of scalding Use protective gloves before carrying out the opera...

Page 13: ...e for EPA regulations placed on the air shroud 1 Model year 2 Engine displacement 3 Power category kW 4 Particulate emission limit g kWh 5 Engine family ID 6 Injection timing BTDC 7 Injector opening p...

Page 14: ...e shown in the figure can be found directly on the engine It contains the following information A Manufacturer s identity B Engine type C Engine serial number D Maximum operating speed E Number of the...

Page 15: ...re Stroke Swept volume Compression ratio Power kW HP Max torque Fuel consumption Oil consumption Capacity of standard oil sump Recommended battery 12V Dry weight Combustion air volume Cooling air volu...

Page 16: ...16 2 Note Dimensions in mm Technical information OVERALL DIMENSIONS KD425 2 Workshop Manual_cod ED0053031750_1 ed_ rev 00...

Page 17: ...wer U1 Standard utilization range of engines rated at 3000 rpm U2 Standard utilization range of engines rated at 3600 rpm The above power values refer to an engine fitted with air cleaner and standard...

Page 18: ...ir inside fuel circuit Clogged tank breather hole Faulty fuel pump Injector jammed Jammed injection pump delivery valve Wrong injector setting Excessive plunger blow by Jammed injection pump delivery...

Page 19: ...ll partial overhaul the following procedures cylinder and piston replacement seat guide and valve refacing crankshaft replacement or grinding bench bearing and connecting rod replacement Danger To avo...

Page 20: ...ricating oil has an affect on engine performance and life If inferior oil is used or if your engine oil is not changed regularly the risk of piston seizure piston ring sticking and accelerated wear of...

Page 21: ...for instance is more performing than a SE oil but less performing than a SG one SAE Classification In the SAE classification oils differ on the basis of their viscosity and no other qualitative chara...

Page 22: ...the flywheel ring Warning Do not tap the end of the extractor when removing the flywheel RECOMMENDATIONS FOR DISASSEMBLING Important To locate specific topics the reader should refer to the index The...

Page 23: ...g screw and remove circlip spring and ball Cut a thread on the inside of the plug body and then withdraw it using a commercial extractor tool fig 8 Extracting crankcase bushes From crankcase fig 6 Fro...

Page 24: ...ts with special detergent and do not use steam or hot water Do not use flammable products petrol diesel etc to degrease or wash components Use special products Dry all washed surfaces and components t...

Page 25: ...s if they are deformed they must be ground to a maxi mum of 0 3 mm Check that there are no cracks or other imper fections in the heads If defects are encountered the heads must be renewed In this case...

Page 26: ...of lower values the valve may strike the piston In the case of values in excess of 1 3 mm the valve seat rings must be replaced Fitting of new seats or valves always requires preparatory grinding Val...

Page 27: ...nternal diameters C D at three different heights fig 18 Maximum permitted taper A B and ovality C D is 0 06mm Diameter of cylinders fig 18 If the diameter of the cylinder does not exceed said values o...

Page 28: ...ton in millimetres Check that the rings move freely in the grooves and check the ring groove clearance using a feeler gauge fig 21 If the clearance exceeds the values shown in the table renew the pist...

Page 29: ...spiration of dust it is good practice to check the condition of the crankshaft 1 Remove the plugs A from the oil passages fig 25 2 Use an appropriately shaped steel punch to clean the inside of the oi...

Page 30: ...scoring and wear Measure the dimensions and compare them to the values in the table below and shown if figures 30 31 Camshaft dimensions fig 30 Assembly clearance between the journals and their housin...

Page 31: ...n good condition fig 32 Make sure that the lubrication holes inside the tappets and push rods are free of dirt Max wear mm Measurement Dimensions mm Fuel pump push rod Check that the surfaces of the f...

Page 32: ...pring Check that the shoes S fig 37 are level and that the springs have not lost their elasticity Renew any excessively worn parts after consulting the spare parts catalogue Supplement and governor sp...

Page 33: ...ssure leak of the pumping unit plunger and valve as follows 1 Connect a pressure gauge with 600 Kg cm full scale to the diesel delivery line fig 40 2 Set the control sleeve nr 12 fig 39 to a mid point...

Page 34: ...ve pin B fig 43 into the internal groove of the control sleeve make sure the helical profile is turned towards the fuel inlet and eccentric pin C fig 43 4 Complete pump assembly with plunger a fig 44...

Page 35: ...there no Diesel fuel accumulates at the nozzle tip after 10 seconds Disassembly and re assembly of injectors Unscrew the ring nut on the injector nozzle using a ring wrench and a special tool as illus...

Page 36: ...nal alternator 12V 400W Recommended battery Refer to tables p 15 Flywheel ring gear Check teeth for wear or damage Fit crown wheel to flywheel by pre heating to 200 250 C Description fig 50 51 1 Ignit...

Page 37: ...er than the value indicated above proceed by checking the alternator and if necessary renewing the voltage regulator Checking the alternator Check 1 with motor stopped the continuity of the windings f...

Page 38: ...cate the coupling parts and protect those that are prone to oxidation Before any intervention the operator should lay out all equipment and tools in such a way as to enable him to carry out operations...

Page 39: ...ly with plate spring lever etc as shown in figure 55 3 Mount the bearing bush gear train side using either a standard press or a made to measure punch as shown in figure 56 Fit the bush by matching th...

Page 40: ...vertically Fit the oil seal ring to the bearing using a suitable diameter tubular punch Fit the bearing into the crankcase after having first interposed an O ring between the contact surfaces fig 63 T...

Page 41: ...ntrifugal force of the governor The balance between the two forces keeps the engine speed virtually constant with respect to load variations Governor tie rod adjustment The length of the tie rod measu...

Page 42: ...tion pipe in order to aid pump priming when the engine is started up for the first time Timing cover Check that the timing markeson the camshaft and crankshaft gears are aligned fig 69 Fit the oil sea...

Page 43: ...ose punched on the connecting rod itself fig 74 Torque the bolts to Now fit the oil pan after first inserting the appropriate gasket between the facing surfaces Cylinders Before fitting the cylinders...

Page 44: ...elative gaskets on the facing surfaces Important Make sure that the oil seal rings are correctly seated in the heads to avoid the risk of oil leaks Align the heads using a metal bar or the exhaust man...

Page 45: ...E or H fig 80 Alternatively the above steps must be performed in their entirety Injection pumps 1 Insert the injection pump tappet D and spacer C into the housings in the crankcase fig 80 2 Assemble t...

Page 46: ...ntermediate point between TDC and IP start of dynamic injection punched onto the flywheel On traditional pumps the static start of injection is the same as the start of dynamic injection IP Should the...

Page 47: ...moves freely along its entire stroke Make the electrical connections as shown in diagram 90 4 With the fuel feed pump cam in the rest position mount the pump and actuate it manually Feed pump 1 Inser...

Page 48: ...ankcase will show up any oil leaks 3 Reconnect the exhaust gas collection pipe to the inlet manifold Checking oil pressure 1 Remove the bolt from the hole in the crankcase and fit a pressure gauge wit...

Page 49: ...s accelerate the engine a few times with no load and check the exhaust fumes Delivery of diesel fuel is correctly calibrated when the exhaust gas is slightly coloured by smoke change the adjustment if...

Page 50: ...s rocker arms valves tappet etc Grease all unpainted parts Loosen belt Wrap the engine in a plastic film Store in a dry place if possible not directly on the soil and far from high voltage electric li...

Page 51: ...51 10 SPECIAL TOOLS For reference check the specific tools manual cod ED0053030770 S to be found at http iservice lombardini it KD425 2 Workshop Manual_cod ED0053031750_1 ed_ rev 00...

Page 52: ...amshaft and central bearings cast iron crankcase Camshaft and flywheel side bearing End gap of compression rings End gap of oil scraper rings Connecting rod and wrist pin Rocker arm and pin Fuel pump...

Page 53: ...8x1 10 14 13 17 20 27 38 45 M 10x1 21 28 26 35 42 56 79 95 M 10x1 25 20 26 24 33 39 52 73 88 M 12x1 25 36 48 45 59 71 95 135 160 M 12x1 5 38 45 42 56 68 90 125 150 M 14x1 5 56 75 70 94 113 150 210 25...

Page 54: ...54 KD425 2 Workshop Manual_cod ED0053031750_1 ed_ rev 00...

Page 55: ...55 KD425 2 Workshop Manual_cod ED0053031750_1 ed_ rev 00...

Page 56: ...mbardini n 2 42124 Reggio Emilia ITALY T 39 0 522 389 1 F 39 0 522 389 503 UK Lombardini U K Ltd 1 Rochester Barn Eynsham Road OX2 9NH Oxford UK T 44 0 1865 863858 F 44 0 1865 861754 FRANCE Lombardini...

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