LOMBARDINI LGA 340 OHC Workshop Manual

Brand: LOMBARDINI

Model: LGA 340 OHC

Category: Engine

Type: Workshop Manual

WORK SHOP

MANUAL

LGA 280-340 OHC Series engines,code 1-5302- 528

SERVICE

LGA 280 OHC

LGA 340 OHC

COMPILER TECO/ATI REG. CODE

1-5302-528

MODEL N°

50805

DATE OF ISSUE

31.07.2001 REVISION 00 ENDORSEDDATE

31.07.2001

1st Edition

SERVICE

PREFACE

Every attempt has been made to present within this service manual, accurate and up to date technical information.

However, development on the Lombardini series is continuos. Therefore, the information within this manual is subject

to change without notice and without obligation.

The information contained within this service manual is the sole property of Lombardini. As such, no reproduction or

replication in whole or part is allowed without the express written permission of Lombardini.

Information presented within this manual assumes the following:

1- The person or persons performing service work on Lombardini series engines is properly trained and equipped to

safely and professionally perform the subject operation;

2- The person or persons performing service work on Lombardini series engines possesses adequate hand and

Lombardini special tools to safely and professionally perform the subject service operation;

3- The person or persons performing service work on Lombardini series engines has read the pertinent information

regarding the subject service operations and fully understands the operation at hand.

GENERAL SERVICE MANUAL NOTES:

1- Use only genuine Lombardini repair parts. Failure to use genuine Lombardini parts could result in sub-standard

performance and low longevity.

2- All data presented are in metric format. That is, dimensions are presented in millimeters (mm), torque is presented

in Newton-meters (Nm), weight is presented in kilograms (Kg), volume is presented in liters or cubic centimeters

(cc) and pressure is presented in barometric units (bar).

COMPILER TECO/ATL REG. CODE

1-5302-528

MODEL N°

50805

DATE OF ISSUE

31.07.2001 REVISION 00 ENDORSED

DATE

31.07.2001 3

WARRANTY CERTIFICATE

Engine manufactured by Lombardini S.r.l., are warranted to be free of defects in workmanship or materials for 12

months from the date of delivery to the first purchaser or non more than two (2) years from date of engine delivery to

the Original Equipment Manufacturer as defined by Lombardini invoicing, whichever occurs firsts, except as defined

below.

Stationary applications, working at constant speed and/or slightly variable speeds, are excluded from the above

terms. Stationary/fixed speed applications will be warranted to be free of material/workmanship defects for a

maximum operational period of 1000 hours or 12months from the date of first purchase, whichever occurs first. The

two (2) year limitation from date of Lombardini invoice will remain intact as described above.

Modification of Lombardini products by the Original Equipement Manufacturer or the end user with respect to cooling

systems, filtration systems, induction systems, exhaust systems, lubrication system, fuel system, fuel system

settings, etc., will require special written warranty agreements. A test certificate/approval by the R&D/Application

engineering department of Lombardini or associated Lombardini companies concerning modified Lombardini products

will entitle Warranty as defined above. Warranty will not be granted on any modified Lombardini product without

special written approval by Lombardini.

Within the above stated periods Lombardini will replace and/or repair, at the option of Lombardini, any part or

component that, upon examination by Lombardini or an authorized Lombardini agent, is found to be defective in

workmanship or materials. Any other responsibility/obligation for different expenses, damages and direct/indirect

losses deriving from the engine use or from both the total or partial impossibility of use, is excluded.

The repair or replacemnt of any component will not extend or renew the warranty period. Direct labor required to make

repairs or to replace components found to be defective in materials or workmanship will be completed at no cost to

the end user. Lombardini in not responsible however for indirect costs of removing/installing the engine assembly.

Further, Lombardini is not responsible for the costs of transportation of the machine or components requiring repair or

for service supplies such as lubricating oils and filters.

Lombardini Warranty obligations will be cancelled if:

- Lombardini engines are applied to a given machine causing working engine parameters outside Lombardini

application guidelines.

- Lombardini engines are not serviced and maintained according to the "USE and MAINTENANCE" booklet.

- Any seal affixed to the engine by Lombardini has been tampered with or removed.

- Engines have been disassembled, repaired or altered by any party other than an authorized Lombardini agent.

- Spare parts used are not original Lombardini.

- Fuel injection system/component failures caused by the use of unauthorized fuel types or poor quality fuels are

not covered under the Lombardini warranty policy.

- Electrical system failures due to the modification of Lombardini supplied harnesses, modification of Lombardini

supplied control panels, OEM/end user supplied/installed relays, controls, etc. are not covered under warranty.

Following expiration of the above stated warranty period(s) and limitations, Lombardini will have no further

responsibility for warranty and will consider our obligation for warranty complete.

The above warranty certificate will be in effect starting July 1, 1993 and cancels/replaces any and all explicit or implicit

warranty policies on the part of Lombardini. The above warranty conditions can from this date forward be modified only

in writing.

REG. CODE

1-5302-528

MODEL N°

50805

DATE OF ISSUE

31.07.2001 REVISION 00 DATE

31.07.2001

ENDORSED

COMPILER TECO/ATL

INDEX

I TROUBLE SHOOTING

II WARNING SIGNS - SAFETY INSTRUCTIONS

III ENGINE IDENTIFICATION

IV TECHNICAL FEATURES

V CHARACTERISTICS

VI OVERALL DIMENSION

VII MAINTENANCE - RECOMMENDED OIL TYPE - REFILLING

VIII DISASSSEMBLY/REASSEMBLY

General information for correct repairs

Engine disassembly

Engine preparation

Flywheel extraction

Head disassembly

Disassembly of camshaft-tappets valves

Timing pulley removal

Timing cover removal

Crankshaft extraction

Cylinder head

Camshaft

Valves - guides - seats - valve spring - tappets

Valves and valve-guides dimensions after assembly in the head

Valves and valve-guides gap

Valve guide

Oil seal ring on valve guide

Valve seats

Valve springs

Tappets

Breather valve

Cylinder

Connecting rod

Piston and rings

Crankshaft

Main journals and crank pin diameter (mm)

Governor and balancing shaft gear command

Balancing shaft

Speed governor

Bearings

Crankcase and timing cover

Recoil starter

Rope and return spring replacement

Oil watch device (optional)

Crancshaft and oil seal rings

Piston and connecting rods

Speed governor

Timing cover

This manual gives the main instructions on how to repair LOMBARDINI LGA 280-340 OHC

gasoline-fuelled engines, updated as of 31.07.2001.

Page 7

" 8-9

" 10

" 11

" 12

" 13

" 14

" 17

23-24

INDEX

COMPILER TECO/ATL REG. CODE

1-5302-528

MODEL N°

50805

DATE OF ISSUE

31.07.2001 REVISION 00 ENDORSED

DATE

31.07.2001 5

INDEX

Timing pulley assembling

Cylinder head assembling

Camshaft assembling and valve clearance adjustment

Timing adjustement and assembling of the toothed belt

Flywheel assembly and coil gap adjustment

Carburetor

Lubrication

IX ELECTRONIC IGNITION

Electronic ignition

Spark plugs

X ELECTRIC STARTING

Electric starting

Electrical start system standard

System checks

Alternator

Rectifier

Starting motor

Battery

Starting panel

Lighting system with alternator

Characteristics with alternator 180 W (optional)

XI REGISTRAZIONI

Engine assembling

Governor lever adjustment

Engine test

Starting with the recoil starter

Electric starting

Carburetor and R.P.M. adjustment

XII STORAGE

Storage

Temporary inactivity

Preparation for starting

XIII INSTALLATION - INCLINATION AND OPERATING LIMITS

Axial load - radial load and maximum overhang

Installation

Inclination and operating limits

XIV TORQUE SETTING

Main torque specifications

Standard bolt torque specifications

XV SPECIAL TOOLS

Special tools

XVI PISTON-CYLINDER OVERSIZE TABLE - TOLERANCES OF CRANKSHAFT JOURNAL

GRINDINGS - TABLE OF CLEARANCES AND ADJUSTMENTS

Piston-cylinder oversize table

Tolerances of crankshaft journal grindings

Table of clearances and adjustments

Page 33

" 34

" 36

" 38

" 39

" 40

" 42

" 43

REG. CODE

1-5302-528

MODEL N°

50805

DATE OF ISSUE

31.07.2001 REVISION 00 DATE

31.07.2001

ENDORSED

COMPILER TECO/ATL

NOTE

COMPILER TECO/ATL REG. CODE

1-5302-528

MODEL N°

50805

DATE OF ISSUE

31.07.2001 REVISION 00 ENDORSED

DATE

31.07.2001 7

TROUBLE SHOOTING I

Listed below are some of the possible causes of engine operating defects.

Carry out simple tests before proceeding with disassembly operations or making substitutions.

TROUBLE SHOOTING

Tank plug breather clogged

Tap clogged

Fuel filter clogged

Dirty carburetor

Carburetor needle valve blocked

Speed governor rod blocked

Grounded spark plug

Broken spark plug lead

Defective coil

Clogged air filter

Low oil level (oil watch alerted)

Air filter chocked

Blocked valves

Worn piston rings

Excessive valve play

Defective oil seals

Worn valve guides

Worn governor spring

Piston seizure

Loose head locking-nuts

Low idling rate

Driving belt broken

POSSIBLE CAUSES

TROUBLE

Noisy

No power

Starts and stops

Does not start

Light or

white smoke

Dark or

black smoke

Hunts

Consumes oil

Overheats

Does not accel.

Spark plug fails

to spark

•

•••

••• ••• ••

••

•• ••••

•

••

••• •

•• ••

••• •••• • ••

••••

•

••

•

REG. CODE

1-5302-528

MODEL N°

50805

DATE OF ISSUE

31.07.2001 REVISION 00 DATE

31.07.2001

ENDORSED

COMPILER TECO/ATL

II WARNING SIGNS - SAFETY INSTRUCTIONS

Failure to comply with these

instructions may result in

damages to persons and

property.

Failure to comply with these

instructions can lead to

technical damage to the

machine and/or installation.

DANGER

WARNING SIGNS

CAUTION

• Lombardini engines are built to provide safe and longlasting performances, but in order to obtain these results it is

essential that the maintenance requirements described in the manual are observed along with the following safety

recommendations.

• The engine has been built to the specifications of a machine manufacturer, and it is his responsibility to ensure that

all necessary action is taken to meet the essential and legally prescribed health and safety requirements. Any use

of the machine other than that described cannot be considered as complying with its intended purpose as specified

by Lombardini, which therefore declines all responsibility for accidents caused by such operations.

• The following instructions are intended for the user of the machine in order to reduce or eliminate risks, especially

those concerning the operation and standard maintenance of the engine.

• The user should read these instructions carefully and get to know the operations described. By not doing so he

may place at risk his own health and safety and that of anyone else in the vicinity of the machine.

• The engine may be used or mounted on a machine only by personnel suitably trained in its operation and aware of

the dangers involved. This is particularly true for standard and, above all, special maintenance work. For special

maintenance contact personnel trained specifically by Lombardini. This work should be carried out in accordance

with existing literature.

• Lombardini declines all responsibility for accidents or for failure to comply with the requirements of law if changes

are made to the engine’s functional parameters or to the fuel flow rate adjustments and speed of rotation, if seals

are removed, or if parts not described in the operating and maintenance manual are removed and reassembled by

unauthorized personnel.

• In addition to all other machine specifications, ensure that the engine is in a near horizontal position when starting.

lf starting manually, ensure that the necessary operations can be performed without any risk of striking against

walls or dangerous objects. Rope starting (except for 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 operations.

• Do not start the machine in closed or poorly ventilated environments. The internal combustion process generates

carbon monoxide, an odourless and highly toxic gas, so spending too long a time in an environment where the

engine discharges its exhaust products freely can lead to loss of consciousness and even death.

• The engine may not be used in environments containing flammable materials, explosive atmospheres or easily

combustible powders, unless adequate and specific precautions have been taken and are clearly stated and

certified for the machine.

• To prevent the risk of fire, keep the machine at a distance of at least one metre from buildings or other machines.

• Children and animals must be kept at a sufficient distance from the machine to prevent any danger resulting from

its operation.

SAFETY INSTRUCTIONS

COMPILER TECO/ATL REG. CODE

1-5302-528

MODEL N°

50805

DATE OF ISSUE

31.07.2001 REVISION 00 ENDORSED

DATE

31.07.2001 9

WARNING SIGNS - SAFETY INSTRUCTIONS II

• Fuel is flammable, so the tank must be filled only when the engine is turned off. Dry carefully any fuel that may

have spilled, remove the fuel container and any cloths soaked in fuel or oil, check that any sound-absorbing panels

made of porous material are not soaked with fuel or oil, and make sure that the ground on which the machine is

located has not absorbed fuel or oil.

• To start the engine follow the specific instructions provided in the engine and/or machine operating manual. Do not

use auxiliary starting devices not originally installed on the machine (e.g. Startpilot systems which utilise ether etc.)

• Before starting, remove any tools that have been used for carrying out maintenance work to the engine and/or the

machine and check that any guards removed have been replaced. In cold climates it is possible to mix kerosene

with the diesel fuel to make the engine easier to start. The liquids must be mixed in the tank by pouring in first the

kerosene and then the diesel fuel. Consult Lombardini technical office for mixture proportions. Petrol may not be

used because of the risk of it forming flammable vapours.

• During operation the surface of the engine reaches temperatures that may be dangerous. Avoid in particular all

contact with the exhaust system.

• Before carrying out any work on the engine, turn it off and allow it to cool down. Do not perform any operation while

the engine is running.

• The liquid cooling circuit is under pressure. Do not carry out any checks before the engine has cooled down, and

even then open the radiator cap or the expansion tank cautiously. Wear protective clothing and glasses. lf there is

an electric fan, do not approach the engine while it is still hot as the fan may come on even when the engine is not

running. Clean the cooling system with the engine turned off.

• While cleaning the oil bath air filter, check that the oil is disposed of in such a way as not to harm the environment.

Any filtering sponges in the oil bath air filter should not be soaked with oil. The cyclone pre-filter cup must not be

filled with oil.

• Since the oil must be emptied out while the engine is still hot (approx. 80°C), particular care should be taken in

order to avoid burns. In any case make sure that oil does not come into contact with your skin because of the

health hazards involved.

• Check that the discharged oil, the oil filter and the oil contained in the oil filter are disposed of in such a way as not

to harm the environment.

• Close the fuel tank filler cap carefully after each fílling operation. Do not fill the tank right up to the top, but leave

sufficient space to allow for any expansion of the fuel.

• Fuel vapours are highly toxic, so fill up only in the open air or in well ventilated environments.

• Do not smoke or use naked flames while filling.

• Take care when removing the oil filter as it may be hot.

• The operations of checking, filling up and replacing the cooling liquid must be carried out with the engine turned off

and cold. Take particular care if liquids containing nitrites are mixed with others not containing these compounds

as this may give rise to the formation of nitrosamines which are a health hazard. The cooling liquid is polluting, so

dispose of in a manner that does not damage the environment.

• During operations which involve access to moving parts of the engine and/or 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 the engine is turned off.

• In order to move the engine use exclusively the eyebolts fitted for this purpose by Lombardini. These lifting points

are however not suitable for the entire machine, so in this case use the eyebolts fitted by the manufacturer.

REG. CODE

1-5302-528

MODEL N°

50805

DATE OF ISSUE

31.07.2001 REVISION 00 DATE

31.07.2001

ENDORSED

COMPILER TECO/ATL

III ENGINE IDENTIFICATION

LOMBARDINI

ENGINE TYPE

SWEPT VOLUME

CUSTOMER CODE

ENGINE IDENTIFICATION NUMBER

COMPILER TECO/ATL REG. CODE

1-5302-528

MODEL N°

50805

DATE OF ISSUE

31.07.2001 REVISION 00 ENDORSED

DATE

31.07.2001 11

TECHNICAL FEATURES

Cylinder

Bore

Stroke

Swept volume

Compression ratio

Standard R.P.M. N DIN 70020

Rating kW NB DIN 6271 ISO 3046

NA DIN 6271 ISO 3046

Max torque

Specific fuel consumption

Tank capacity

Housing oil capacity

Dry weight

Spark plug

Ignition system

Cooling system

Type of engine

TECHNICAL FEATURES LGA 280-340 OHC

ENGINE TYPE

cc.

RPM

kW/HP

Nm-Kgm

g/kW h - g/HP h

Kg.

LGA 280 LGA 340

275

8.5 - 1

3000 - 3800

6.0/8.1 - 6.6-9.0

5.6/7.6 - 6.3/8.5

5.2/7.1 - 5.9/8.0

19 - 1.94

329 - 242

1.2

112-2100-067

Electronic

Forced air

4-stroke

integral

camshaft

338

8.5 - 1

3000 - 3800

7.4/10 - 8.1/11

6.9/9.4 - 7.7/10.4

6.6/8.9 - 7.3/9.9

23.7 - 2.4

342 -251

1.2

112-2100-067

Electronic

Forced air

4-strokes

integral

camshaft

LGA 280

LGA 340

REG. CODE

1-5302-528

MODEL N°

50805

DATE OF ISSUE

31.07.2001 REVISION 00 DATE

31.07.2001

ENDORSED

COMPILER TECO/ATL

CHARACTERISTICS

CHARACTERISTICS POWER, TORQUE AND SPECIFIC FUEL CONSUMPTION CURVES

N (80/1269/CEE - ISO 1585) AUTOMOTIVE RATING : Intermittent operation with variable speed and variable load.

NB (ISO 3046 - 1 IFN) RATING WITH NO OVERLOAD CAPABILITY: continuous light duty operation with constant speed and variable

load.

NA (ISO 3046 - 1 ICXN) CONTINUOUS RATING WITH OVERLOAD CAPABILITY: continuous heavy duty with constant speed and

constant load.

MN Torque curve (at N powe)r.

MB (in NB curve)

MA (in NA curve)

C Curve of specific fuel consumption measured at power N.

The above power values refer to an engine fitted with air cleaner and standard muffler, after testing and at the environmental conditions of 20°C

and 1 bar.

Max. power tolerance is 5%.

Power decreases by approximately 1% every 100 m di altitude and by 2% every 5°C above 20°C.

Note: Consult LOMBARDINI for power, torque curves and specific consumptions at rates differing from those given above.

LGA 280 LGA 340

COMPILER TECO/ATL REG. CODE

1-5302-528

MODEL N°

50805

DATE OF ISSUE

31.07.2001 REVISION 00 ENDORSED

DATE

31.07.2001 13

OVERALL DIMENSIONS - OPTIONAL P.T.O. AND FLANGES

POWER TAKEOFFS AND SPECIAL FLANGING

OVERALL DIMENSIONS

Note: The values are given in mm

REG. CODE

1-5302-528

MODEL N°

50805

DATE OF ISSUE

31.07.2001 REVISION 00 DATE

31.07.2001

ENDORSED

COMPILER TECO/ATL

MAINTENANCE - RECOMMENDED OIL - FUELS AND LUBRICANTS

VII

10 20 25 50 100 300 500 1000 2500

MAINTENANCE

CLEANING

INSPECTION

REPLACEMENT

INTERVAL (HOURS)

COMPONENT

OPERATION

Air filter cartridge

Fuel filter

Cylinder and head fins

Oil level in housing

Distance of glow plug electrodes

Valve play

Timing belt

Oil in housing

Paper cartridge of air filter

Timing belt

•

Failure to carry out the operations described in the table may lead to technical damage to the machine

and/or system

To avoid explosions or fire outbreaks, do not smoke or use naked flames during the operations.

Fuel vapours are highly toxic. Only carry out the operations outdoors or in a well-ventilated place.

Keep your face well away from the plug to prevent harmful vapours from being inhaled. Dispose of fuel in the

correct way and do not litter as it is highly polluting.

FUEL

When refuelling, it is advisable to use a funnel to prevent fuel from spilling out. The fuel should also be filtered to

prevent dust or dirt from entering the tank.

Use PREMIUM gasoline or UNLEADED PREMIUM gasoline of the type used in cars. Use of other types of fuel could

damage the engine.

The octane rating of the fuel must be higher than 95 to prevent difficult starting.

Do not use old, dirty gasoline or oil-gasoline, water-gasoline mixtures since this would cause serious engine faults.

The tank capacity is: 6 l.

COMPILER TECO/ATL REG. CODE

1-5302-528

MODEL N°

50805

DATE OF ISSUE

31.07.2001 REVISION 00 ENDORSED

DATE

31.07.2001 15

RECOMMENDED OIL

AGIP SINT 2000 5W40 specification API SJ/CF ACEA A3-96 B3-96

MIL-L-46152 D/E.

ESSO ULTRA 10W40 specification API SJ/CF ACEA A3-96 MIL-L-

46152 D/E.

In countries where AGIP and ESSO products are not available, use

API SJ/CF oil for gasoline-fuelled engines or oil that complies with

military specification MIL-L-46152 D/E.

OIL SUPPLY (liters) LGA 280 - LGA 340

Standard oil sump lt 1.2

ACEA SEQUENCES

A = Gasoline (petrol)

B = Light Diesel fuels

E = Heavy Diesel fuels

Required levels :

A1-96

A2-96

A3-96

B1-96

B2-96

B3-96

E1-96

E2-96

E3-96

VII

MAINTENANCE - RECOMMENDED OIL - FUELS AND LUBRICANTS

The engine could be damaged if allowed to operate with insufficient oil. It is also dangerous to add too much oil as its combustion

could sharply increase the rotation speed.

Use a suitable oil in order to protect the engine.

The lubrication oil influences the performances and life of the engine in an incredible way.

Use of an inferior quality oil or failure to regularly change the oil will increase the risk of piston seizure, may make the compression

rings jam and will lead to rapid wear on the cylinder liner, the bearings and all other moving parts. Engine life will also be notably

reduced.

Oil viscosity must suit the ambient temperature in which the engine operates.

Old oil can cause skin cancer if repeatedly left in contact with the skin and for long periods of time. If contact with the oil is

inevitable, you are advised to thoroughly wash your hands with soap and water as soon as possible.

Appropriate protective gloves etc should be wore during this operation.

Old oil is highly polluting and must be disposed of in the correct way. Do not litter.

Engine oil fuelling

Set the engine on a flat surface, then pour in oil up to the max. level mark on the plug dipstick.

If the engine has an oil-cooled filter, check the oil level in the filter sump and if necessary, top up with the same type of oil as used to

lubricate the engine.

GRADE

CCMC G- 2

CF CE CD CC CB CA SA SB SC SD SE SF SG

DIESEL BENZINA - ESSENCE - PETROL

BENZIN - GASOLINA

CCMC G- 3 G- 5

CCMC PD - 1 / PD - 2

CCMC D- 2

D- 4 CCMC D- 3

D- 5

MIL - L - 2104 D

MIL - L - 2104 E

MIL - L -46152 C

MIL - L- 46152 D/E

MB 226.1 MB 226.5

MB 227.1 MB 227.5

228.3 MB 228.1

VW 501.01

VW 500.00

SHAPI

G- 4

VOLVO VDS

MAN QC 13-017

VW 505.00

SAE 20W SAE 30SAE 40

SAE 10W-30

SAE 10W-40

SAE 10W-60

SAE 15W-40 mineral based

SAE 15W-40 semi-synthetic based

SAE 20W-60 semi-synthetic based

SAE 5W-30 synthetic based

SAE 0W-30 synthetic based

SAE 5W-40 synthetic based

30 -

25 -

20 -

15 -

10 -

50+

10 +

15 +

20 +

25 +

30 +

35 +

40 +

SAE 10W

REG. CODE

1-5302-528

MODEL N°

50805

DATE OF ISSUE

31.07.2001 REVISION 00 DATE

31.07.2001

ENDORSED

COMPILER TECO/ATL

NOTE

COMPILER TECO/ATL REG. CODE

1-5302-528

MODEL N°

50805

DATE OF ISSUE

31.07.2001 REVISION 00 ENDORSED

DATE

31.07.2001 17

DISASSEMBLY/REASSEMBLY VIII

DISASSEMBLY AND REASSEMBLY

Besides disassembly and reassembly operations this chapter also

includes checking and setting specifications, dimensions, repair and

operating instructions. Always use original LOMBARDINI spare parts

for repair operations.

GENERAL INFORMATION FOR CORRECT REPAIRS

- In order to work quickly and safely, strictly observe the instructions in the manual and the following general rules:

- Lock the machine in position before disassembling the engine.

- Disconnect the battery cables (if the engine is equipped with electric starting).

- Always use suitable tools in order to avoid damaging engine parts.

- Use a plastic mallet to separate connected parts.

- When disassembling the engine, mark the parts that are not provided with reference marks in order to facilitate successive

assembly operations.

- Clean disassembled parts with petrol and compressed air

- Always replace gaskets, oil seals, washers and locknuts. Before re-assembling, lubricate moving parts and contact

surfaces.

- Respect torque wrench settings when tightening screws.

- Use always LOMBARDINI original spare parts.

ENGINE DISASSEMBLY

lf the engine is mechanically worn-out but the outside parts are still in good condition (tank, casing, flywheeI, coil, carburetor,

air filter, exhaust, fan cowl, cylinder head), the use of a “Short-Blocks” is advised (composed of crankcase, crankshaft,

connecting rod, piston, timing cover) already enclosed and prepared to be completed by the outside parts. Once assembly

operations have been completed, proceed with setting up.

ENGINE PREPARATION

After having drained off the oil from the engine and emptied the fuel tank, place the engine on a work bench and

disassemble the outside parts: tank, exhaust, air filter, carburetor, casing, recoil starter and fan cowl.

During the demounting phases, pay particular attention to

prevent the flywheel from dropping as this could seriously injure

the operator.

Wear protective goggles when removing the flywheel ring.

FLYWHEEL EXTRACTION

Loosen the flywheel locknut (remember that the thread is RIGHT

HANDED), remove the washer and pulley belt. Using the puller

CODE 3595.048 on page 42, remove the flywheel (fig. 1).

HEAD DISASSEMBLY

Do not disassemble when hot to avoid deformation.

Remove the belt cover casing, loosen the tightener and timing belt, remove the timing pulley loosening the screw that fixes it

to the camshaft, and the relative key, remove the toothed belt internal protective casing.

Using a allen wrench, loosen the 4 screws M 10 that fix the casing to the engine.

WARNING: it is advised to replace the timing belt after removal, even if this means anticipating the expiry term.

(See tab. pag. 14)

WARNINGS!

During repair operations, when using

compressed air, wear eye protection.

REG. CODE

1-5302-528

MODEL N°

50805

DATE OF ISSUE

31.07.2001 REVISION 00 DATE

31.07.2001

ENDORSED

COMPILER TECO/ATL

DISASSEMBLY/REASSEMBLY

VIII

DISASSEMBLY OF CAMSHAFT - TAPPETS VALVES

Remove the tappet cover, rotate the camshaft so that the cams face

upward, remove the side support, extract the camshaft (fig.2).

Remove the tappets and, with tool CODE 1460.113 on page 42 , remove

the valve cotters; then extract the valves from the valve guides.

TIMING PULLEY REMOVAL

Use extractor CODE 1460.114 on page 42 and remove the timing pulley

as shown in fig. 3.

TIMING COVER REMOVAL

Loosen the M 8 screws that fix the timing cover to the crankcase, using puller CODE 3595.048 on page 42, position the central

screw on the opposite side from that used to extract the flywheel, tighten the two screws in the threaded holes on the timing cover

(fig. 4a).

DRIVE SHAFT EXTRACTION

After the completion of operations, loosen the connecting rod screws, slide out the piston and extract the drive shaft.

Do not demount and remount when hot to avoid deformations.

CYLINDER HEAD

Made in die-cast aluminium alloy with inserted valve seats which are

made of special cast iron of high nickel-chromium content. They are

introduced with negative allowance into the relative seats on the head.

The valve guides are inserted and replaceable; special cast iron for the

intake valve and bronze for the exhaust valve. Clean all carbon deposits

from the head and check that the head face P fig. 4b is not deformed.

lf deformed, grind the working face by removing not more than 0.25 mm.

4a 4b

COMPILER TECO/ATL REG. CODE

1-5302-528

MODEL N°

50805

DATE OF ISSUE

31.07.2001 REVISION 00 ENDORSED

DATE

31.07.2001 19

DISASSEMBLY/REASSEMBLY VIII

CAMSHAFT

Check that the cams and pins are not worn or scored. Slight indentations

or scoring can be taken up using a fine file and finished with the same

type of emery cloth. The pin diameter values and other main camshaft

dimensions are shown in the table in fig. 5.

All engines are fitted with centrifugal compression release; check the

smoothness of the counter-weight and the correct position of the spring

(fig.6).

The protusion of the pin from the cam contour must be between 0.50

÷ 0.60 mm with the device engaged.

N.B.: up to serial No. 11276 the protusion of the pin from the cam was

0.65-0.75 mm. Camshaft with protusion of the pin between 0.50-

0.60 mm will be delivered as spare parts.

VALVES - GUIDES - SEATS -VALVE SPRINGS -TAPPETS

After disassembly and cleaning with a metal brush, check that the

valves heads are not deformed, burned or worn in the seats: replace

the valves if damaged.

If the general condition is good, reset the face track P in the seat with

a grinding of:

90' exhaust - 90' intake for engine LGA 280 OHC

90' exhaust - 121' intake for engine LGA 340 OHC

Check the guides, valves, seats after assembly.

N.B.: Valve seats with angles of 90° (exhaust) and 121° (intake) will be

used in the LGA 280 OHC too.

Please check tecknical informative sheet for introdution date

Valves and valve-guides dimensions after assembly in the head.

nominal D. (mm)

A Inlet valve 7 -0.013

-0.035

B Exhaust valve 7 -0.030

-0.045

C Inlet valve-guide 7 -0.025

+0.015

D Exhaust valve-guide 7 +0.025

+0.015

REG. CODE

1-5302-528

MODEL N°

50805

DATE OF ISSUE

31.07.2001 REVISION 00 DATE

31.07.2001

ENDORSED

COMPILER TECO/ATL

DISASSEMBLY/REASSEMBLY

VIII

Valves and valve-guides gap

NOMINAL LIMIT

C - A 0.028 - 0.070 0.14

D - B 0.045 - 0.080 0.14

VALVE GUIDES

Check that the valve guides are not scored, show signs of seizing or

carbon deposits. Cheeking of the valve guides wear (fig. 10) can be

carried out using a plug go-no-go gauge with pitch code 1460.103 on

page 42.

Internal valve-guides diameter after assembly in the head:

min 7.015 mm - max 7.025 mm

valve-guides gauge diameter:

7.010 mm passes - 7.097 mm does not pass

lf the diameter of the guide exceeds the plug diameter, replace the

guide. In order to extract the valve guide from the seat, use puller code

1460.104 on page 42, after having removed the safety ring.

OIL SEAL RING ON VALVE GUIDE:

Check that the rings are intact and still sufficiently elastic before re-

assembling. It is advised to replace these parts. For the assembling,

(fig. 11) use the tool code 1460.108 on pag. 42.

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LOMBARDINI LGA 340 OHC Workshop Manual

Brand: LOMBARDINI

Model: LGA 340 OHC

Category: Engine

Type: Workshop Manual

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LOMBARDINI LGA 340 OHC Workshop Manual

LOMBARDINI LGA 340 OHC Workshop Manual

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