Lombardini IM 250 Workshop Manual Download Page 31

VIII  - REGLAGES  ET  ESSAIS 

CONTROLES  AVANT  DEMARRAGE 

Après  achèvement  du  montage,  procéder  aux  suivantes  opé-. 
rations: 

- Fixer  le  moteur  sur  une  base,  à  la  machine  entra1née ou  au
frein  dynamomètrique.

-

Etablir  le  niveau  d'huile  dans  le  carter  et  dans  le  fìltre  à  air 

à  bain  d'huile  et  remplir  le  réservoir  (voir  à  page  4). 

- Ouvrir le robinet (si prévu).

En  cas  de  remplacement  du  carburateur  et  de  révision,  ef­

fectuer  un  premier  réglage  en  fermant  complétement  la  vis
réglage  mélange  et  en  la  dévissant  ensuite  d'environ  trois
tours.

- Fermer  le  papillon  starter  ou  l'amener  dans  la  position  in­

termédiaire  (voir  à  page  16).

-

Disposer  l'accélérateur  à  1 /3  de  la  course.

- Si  prévu,  connecter  le  pont  de reddresseme.rit  à  masse  et  à 

la  batterie,  com me  par  schéma  aux  pages  20-23. 

Le  fonctionnement  sans  batterie  provoque  /'avarie  du  pont  en  peu 

de 

secondes. 

ESSAI  DE  FONCTIONNEMENT  A  VIDE 

Tous  les réglages sont  à  effectuer  avec  un  compte-tours  sur  un 
moteur  chaud. 

La  duréee  de l'essai  dépend  des  pièces  à  roder.  Après  une  ré­

vision  complète  l'essai  peut  durer  jusqu'à  90  minutes. 

- Démarrer  le  moteur  et  ouvrir  graduellement  le  papillon 

starter.

Pour 

/es  moteurs  à 

pétrole, 

démarrer  à  /'essence 

et  réchauffer 

le  moteur  pour  environ  deux 

minutes 

et  disposer  ensuite  le  ro­

binet  pour  l'alimentation 

à 

pétrole. 

-

Maintenir  le  régime  à  2000  t/1' pendant  10  minutes  environ. 

-

Actionner  l'accélérateur  en  s'assurant  de  son  coulissement. 

Ne  pas  agir  directement  sur  le  papillon  mélange  ou  sur  la  biellette 
car 

en 

exc/uant  l'action 

du 

régulateur 

on 

peut 

atteindre 

des  régimes 

de  tours  incontriìlés. 

Pour  une  commande 

à 

distance  il  faut  un  flexible  avec  levier  ou  un 

dispositif  similaire  qui  permette  d'accélérer 

à 

travers  le  régulateur. 

REGLAGE  DU  MELANGE  AU  RALENTI 

Amener  le  régime  à:  1.000...:.. 1.100 t/1',  en  agissant  sur  la  vis 
de réglage A (Fig. 94)  et en réglant en mème temps le  mélange 
avec  la  vis  B  sur  la  courbe  (Fig.  95). 

En 

vissant la vis B le 

mé/ange 

s'appauvrit, 

en 

la 

dévissant 

il s'enrichit. 

Après  quelque  accélération,  le  ralenti  ne  doit  pas  changer. 

33 

SERIE  IM 

VIII  - SETTING  AND  TESTING 

PRE-STARTING  CHECKS 

Having  completed  engine  assembly,  proceed  as  follows: 

-

Bolt engine  on  the  dynamometer  stand  or  couple  it to the 

driven  machinery. 

- Pour cii  engine and air cleaner up to the proper  levels.  Fili 

fuel  tank  up  (see  pag.  4).

- Turn  shut-off-valve  to  open  position,  where  provided.  After 

generai  overhaul  or  when  replacing  carburettor,  effect  a 

preliminary  adjustment  by  turning  idle  mixture  screw  fully 

in  and  turning  it  back  3  turns.

- Shut choke valve or piace valve in mid position  (see page 16).

- Piace  accelerator  on  by  1 /3  of  its  trave I. 

-

Connect rectifying bridge to ground and to battery terminal, 

where engine is equipped with electric starting - See pag. 20-23 

for  wiring  diagrams.

Even 

few  seconds  of  engine  operation  with  battery disconnected, 

causes  rectifying  bridge  failure. 

IDLE  RUNNING  TEST 

Ali  settings should be  made with a hot engine and with the aid 
of  a  tachomete r. 

Testing  time  depends  on  parts  to  be  r�n-in  and  in  case  of  ge­
nerai  engine  overhaul  test  may  last  90  minutes. 

-

Start  the  engine  and  gradually  open  choke  valve. 

-

Far  engines  operating  on 

kerosene 

fuel, 

start  engine  on 

gasoline 

and 

warm  up  far  approximate/y 

minutes  before  turning  shut-off­

valve 

to  kerosene 

feeding  position. 

Set  and  keep  engine  speed  at  2.000  R.P.M.  for  10  minutes. 

- Accelerate  engine  repeatedly  to  ascertain  that  throttle  valve 

and  linkages  work  smoothly.

Never  operate  throttle  valve  directly  or  through  connecting 

/inks, 

because  the 

exc/usion 

of  governar 

speed 

contro/  would 

cause  engine 

to  overspeed  to 

dangerous  /eve/s. 

Far  accelerator 

remote  contro/ 

f/exible cab/e is employed with 

some 

sort of 

contro/ 

lever or similar 

device  that  allows  engine 

speed 

contro/  through  the  governar. 

IDLE  MIXTURE  AND  SPEED  SETTING 

Set  engine  speed  to:  1.000 ...;- 1.100  R.P.M. 

Above  setting  is  carried  out  through  adjustment  of  throttle 
valve  set  screw  A  (Fig.  94)  and idle  mixture  screw  B  (Fig.  95). 

By  turning  screw  B  in 

a  /ean 

mixture 

is obtained and a 

rich  mixture 

is 

fed 

to 

the  engine  when  screw  is  turned  out. 

MANUEL  D'ATELIER  - WORKSHOP  MANUAL  - WERKSTATTHANDBUCH 

VIII  - NACHSTELLEN  UND  PRUFEN 

KONTROLLEN VOR  DER  ERSTEN INBETRIEBNAHME 

Nach  der  Montage  folgende  Arbeiten  durchfi.ihren: 

- Meter  auf  einem  festen  Untersatz  befestigen,  oder  mit  der

Maschine  oder  der  PrLlfstandbremse  verbinden. 

- 01 im Motorgehause und im Luftfìlter auf den richtigen Stand

bringen.  Tank  mit  Kraftstoff fi.illen  (siehe  S.4).

- Kraftstoffhahn éiffnen,  falls vorhanden.  Bei  Ersatz  oder  Uber­

holung  des Vergasers eine Voreinstellung  durchfi.ihren, indem
man  die  Leerlaufgemischregulierschraube  véillig  zudreht 
und  sie  dann  um  drei  Umdrehungen  wieder  aufschraubt. 

- Starterklappe  schliessen,  oder  sie  in  Mittelstellung  bringen 

(siehe  S. 

16). 

Beschleuniger  um  1 /3  seiner  Drehung  verstellen.

- Gleichrichterbriicke,  falls  vorhanden,  mit  der  Masse  und  der

Batterie  verbinden,  wie  aus  dem  Schaltschema  von  S.  20-23 

ersichtlich  ist.

Der 

Betrieb 

mit 

ausgescha/teter  Batterie 

kann  der 

Briicke  inner­

halb  van  wenigen 

Sekunden 

schaden. 

LEERLAU FPROBE 

Alle  Nachstellungen  miissen  bei  warmen  Meter  mit  Hilfe. 

Drehzahlmessers  durchgefi.ihrt  werden. 

Die  Probendauer  hangt  von  den  einzulaufenden  Teilen  ab. 
Nach  einer  GeneralUberholung  kann  sie  bis  zu  90  Minuten 
betragen. 

-

Meter  anlassen  und  Starterklappe  allmahlich  éiffnen.

-

Bei  Petro/eum-Motoren  zuerst  mit  Benzin  anlassen.  Motor  ca. 

Minuten  warm /aufen /assen. 

Dann 

Kraftstoffhahn auf  Petroleum 

umscha/ten. 

- Drehzahl  ca.  10  Minuten  auf  2000  U/min  lassen.

- Beschleuniger  betatigen,  um  nachzuprLlfen,  ob  die  Drossel-

Klappe frei  beweglich  ist.

Niemals 

direkt 

auf 

Drosse/k/appe 

oder  Hebelsystem 

einwirken, 

da 

bei  Ausschluss  der  Reglerwirkung  unkontrollierte  Drehzahlen 

auftreten 

konnen. 

Bei  Motoren 

mit 

Fernsteuerung  des  Beschleunigers  muss 

man 

iiber 

ein 

Bowdenzugkabel 

mit 

Hebel  oder  uber  eine  ahnliche  Vorrichtung 

verfiigen,  die  eine  Besch/eunigung  durch  den  Regler  erméiglicht. 

LEERLAUFGEMISCHREGULIERUNG 

Drehzahl  bringen  auf: 

1.000 ...;- 1.100  U/min. 

indem  man  auf  die  Einstellschraube  (A)  einwirkt.  Gleichzeitig 
muss  man  das  Gemisch  mittels  der  Leerlaufgemischregulier­

Schraube 

(B) 

am  AnsaugkrLlmmer  einstellen  (Abb.  94,  95 ). 

Beim  Anziehen  der  Regulierschraube 

(B) 

wird 

das 

Gemisch  magerer , 

beim  Aufdrehen  wird  es  fetter. 

Fig.  94 

Fig.  95 

33 

Summary of Contents for IM 250

Page 1: ...serie IM monuel d atelier workshop monuol werkstotthondbuch servt Ce _ _ _ ___ D ___ __ ____ ...

Page 2: ...3 Benzin Pétrole IM 302 7 9 5 4 4 5 1 5 5 6 5 3 600 1 51 2 300 Kerosene Petroleum Essence IM 350 7 9 5 7 6 1 7 8 3 600 2 03 1 800 Gasoline Benzin Essence IM 351 82 66 349 5 3 7 6 1 5 5 6 5 2 400 2 03 1 800 Gasoline 23 Benzin Pétrole IM 352 7 9 5 4 4 5 1 6 5 7 5 3 600 1 87 1 800 Kerosene Petroleum N B Sauf indicacions contraires les régles de réparations sane valables pour cous les moceurs de la sé...

Page 3: ...omplaints that may be encountered during the service ife o the engine Be ore attempting disassembly or making any rep acement always check the easiest and most obvious things irst Die Tabelle enthalt die wahrend des Betriebes am haufìgsten auftretenden Stbrungen In jedem Fall ist es empfehlenswert vor der Demontage oder dem Auswechseln die einfachsten Kontrollen systematisch durchzufLlhren CAUS E ...

Page 4: ...s may be found in the Master Parts Manual ENGINE IDENTIFICATION Engine type is marked on the plate placed on the air shroud The serial number is generally punched on the crankcase cast ing below the throttle contro assernbly Fig 1 ENGINE PLACEMENT Bolt engine on to overhauling stand using engine rnount threaded holes on carburettor side DISASSEMBLY Disassemble tank silencer air cleaner pulley and ...

Page 5: ...pring from governor lever When disassembl ing case cover pay attention to gasket between crankcase and cover CAMSHAFT To remove the camshaft Disassemble breaker push rod Match timing marks on crankshaft and camshaft with piston at T D C of compression stroke Turn engine upside down and withdraw the camshaft With drawal of camshaft may be accomplished with engine in normai position by inserting a s...

Page 6: ...ves 5 Spring plates 6 Springs 7 Spring locking plates 8 Tappets 9 Cylinder head VALVES GUIDES SEATS After disassembling and descaling with a wire brush check condition of valves and rep ace if valve mushrooms are out of sha pe cracked or too worn To reuse slightly worn valves we recommend restoring seat area D with a 45 valve grinder Dimension of va ves guides and seats after assembling in crank c...

Page 7: ...ve or a pilot drift We recommend having this job done by a skilled MACHINING SHOP Seat and valve grinding or replacement always require lapping VALVE SPRINGS Check if springs are damaged or have lost their elasticity Spring free length must be 40 5 è 41 5 rnm H Fig 11 Springs compressed under a load of 17 0 è 17 5 Kg must have a length of 24 mm Repiace springs for lower length values CRANKCASE BRE...

Page 8: ...beyond 0 10 mm rebore to next oversize and install oversize piston and rings as per dimension table PISTON AND RINGS Measure piston skirt diameter at 2 mm from base perpendi cularly to gudgeon pin Fig 17 Skirt wear not to exceed 0 05 mm Piston oversize scale mm Series Nominai 1 st Oversize 2 nd Oversize IM 250 69 87 69 89 70 37 70 39 70 87 70 89 IM 300 75 89 75 91 76 39 76 41 76 89 76 91 IM 350 81...

Page 9: ...amaged On electric started engines flywheels are not interchangeable with the standard type When replacing see the Master Parts Catalogue RING GEAR Ring gear is fìtted to the flywheel of engines equipped with starter motor Check for worn or damaged teeth lf necessary replace ring gear as follows Heat up ring gear along inner circumference using a gas heating torch and remove from flywheel with a p...

Page 10: ... or grinding make a Magnaflux check of the shaft to detect surface cracks After clearing or grinding the hardness of the journals should be SO è 55 Rockwell cf bel ow this value grind to next undersize or replace shaft Radius of shaft fillets must be 2 7 è 3 0 mm and journal surface must be neatly finished with out helical grooves and have a roughness of 0 2 è 0 4 micron Crankpin and end bearing d...

Page 11: ...the series Camshaft with automatic decompressor The automatic decornpression device is fitted to camshafts of engines equipped with rewind starter or eiectric starting The device makes starting of the engine easy allowing flywheel to pickup momentum being the exhaust valve kept open Page 18 and 19 As camshaft rotates faster centrifugai force knocks decom pressor device off and the engine starts Ch...

Page 12: ... spring tension is established with consequent change of engine speed Governor Check Check gear governor weights and their housings for burrs Axis of weight pins must be perpendicu ar to gear axis Drive rod surface on which weight skids work must be smooth and normai to the hole Play between drive rod and journal must be kept within 0 10 0 20 rnrn Should play be higher replace drive rod LUBRICATIO...

Page 13: ...eam of air rushing through idle passage ldle rnixture adjustement screw 4 is to set best slow running speed Fig 34 C Acceleration when slightly increasing throttle opening vacuum at the idle channel is partly destroyed Fuel feeding from idle port almost stops A small hole progression hole 5 communicating with the idle channel provides a fuel supply as soon as the throttle valve 2 starts to open Fi...

Page 14: ... turn freely Spindle diameter must be 5 975 7 5 988 mm Replace spindle if diameter is smaller or if spindle to housing clearance exceeds 0 20 mm At fully closed position of the throttle valve distane from idle discharge hole to the valve face should be 0 04 è 0 06 mm replace cover for different values Check that choke valve is not worn and that butterfly fully turns throughout its travel Fig 37 Ch...

Page 15: ... high tension ignition current by rapidly stopping flow of current in the primary winding Components in Fig 40 1 Spark plug 2 Stop pushbutton spring 3 Stop push but ton 4 Condenser 5 Armature 6 lnductor magnet 7 Crankshaft 8 Cam follower 9 Breaker 10 Flywheel 11 Pushrod 12 Armature core 13 Camshaft Checks Coi check with an ignition coil tester spark gap replace if found faulty Electric circuits sp...

Page 16: ...lli cw 4 N cw 2 N Bosch w 10 A w 12 A Champion L 90 KLG F 50 Clean spark plug electrodes using a wire brush and remove dirt with compressed air Reset electrodesgap to 0 7 0 8 mm Fig 45 Replace spari plug every 300 hours and whenever insulator is cracked or ground electrode is badly worn Breaker Check breaker points replace points assembly if contact tips are badly burnt or damaged A light oxide co...

Page 17: ...ly unwound rope Rewind starter tension with completely wound rope must be 1 2 1 5 Kg after initial friction has been taken up Fig 47 Replace spirai spring 7 if found broken Spare springs are supplied coiled up and tied with wire Do not remove wire until spring is correctly seated and mak e sure that spring winds up when turning pulley in direction of engine rotation ELECTRICAL EQUIPMENT Electrical...

Page 18: ... 7000 9727 01 Fig 50 Rest one end of tool horizontally on rnagnet poles Hold tool slider on casing rnatching rnarks C and A Let slider free if it is not pulled in by the rnagnet rotor is demagnetized and must be replaced Chech that stator windings have no unsoldered connection burn marks or earthed wires replace stator if faulty With an Ohrnmeter check for continuity between alternator leads and f...

Page 19: ...ter motor The motor type is AMERICAN BOSCH 11277 28 MO 20 SM 0 22 HP output Fig 55 shows rating curves P starting torque M R P M and voltage V at starter motor terminals in relation to current absorbed Amp and battery capacity at 20 C ambient tem perature For repairs and overhauls contact BOSCH service Stations Battery The 12 Volt battery must have a minimum capacity of 36 Ah at the ten hour disch...

Page 20: ...ce a 0 5 mm diameter copper wire te act as fuse Connect a 15 Amp D C ammeter in series between termi nal 8 30 on regulator and battery positive terminal Fig 57 lf necessary start engine a few times or switch lights on unti battery tension drops below 13 Volts Diagram in Fig 58 shcws current values Amp referred te engine speed A and starter generator speed B with a constant 12 5 Volts battery volta...

Page 21: ...attery charge Wiring diagram and components for 12 V 50 Watt alternato Fig 61 1 Armature winding 2 lnductor 3 Rectifying bridge 4 Battery not supplied 5 Utilizers 6 Keyswitch Connect lights for a totaI current absorbtion of 48 50 Watts and set engine speed at 3600 R P M Tension should be approx imately 12 Volts easily detected by observing the light bright ness lnsert a 5 10 Amp D C ammeter betwee...

Page 22: ...gm when engine is equipped wi th alternator OIL SEALING RINGS Seals must be replaced if marks of burns or cracks and sealing faces are detected Always renew seal rings when disassembling bearings P T O side CRANKSHAFT Heat ball bearing in oven to 120 7130 C and press it in For checks and replacements see pag 11 Mount cranksaft complete of ball bearing into crankcase placing on the threaded end the...

Page 23: ...TIMING Piace piston at T D C and turn crankcase upside down to insert tappets lnsert camshaft with thrust face flat section facing tappets only position for assembly of shaft Fig 70 and return crankcase to upright position Match timing marks on camshaft gear and drive gear On engines equipped wich rewind starter or electric Harter assemble camshaft with automatic decompressor lf gears do not bear ...

Page 24: ...sert it changing meshing position unti correct value is obtained IGNITION Coil and breaker lnsert the pushrod on its seat of the crankcase Mount pushrod plate and breaker tightening the three screws Set maximum opening gap of points to 0 65 0 70 mm by acting on adjusting screw of stationary contact Assemble ccii without tightening bolts Connect a timing light to switch on when points are closed Tu...

Page 25: ...ening nuts to 4 Kgrn Spark plug torque to 3 5 Kgm Starter motor where provided tighetening nuts to 1 0 Kgm Airshroud Head cooling air baffle Carburettor and rnanifold assembly after tielink and spring have been connected to the throttle contro lever Torque nuts to 0 8 Kgrn Connect breather tube to air cleaner and assernble air cleaner Throttle housing hanging up again the springs to the car burett...

Page 26: ...Fig 80 and act on valves untiI a circular mark is 0btained on the white paper Tighten nut D Fig 80 avoiding to move the valves Adjust gas outflow with engine stopped acting on adjust ing screw A Fig 81 Connect a pressure gauge to out flow elbow and see that gas pressure dces not exceed 10 15 mm of water column Similarly with soap foam applied to outflow see that bubble made by gas swalls slowly if...

Page 27: ... 11 Housin Reduction gear P T O rotates anticlockwise i e same dire tion of engine P T O Reduction gears are suitable either f g e or direct or Kbelt drive Maximum Kbelt bending load on sh3ft end is 100 Kg and distance from pulley center line coupling face must not exceed 35 mm with the pulley pit to eh diameter equa to 90 mm Check nd Replace ball bearings if radiai play is excessive or if balls a...

Page 28: ...y Diameter 74 94 74 97 104 93 è 104 96 Out of round a b 0 005 Heat ball bearing in oven to 80 C and press it into gear shaft Assemble gear in the case and lock it with stop plate Tighten stop plate screws to 0 8 Kgm Fig 88 Side clearance bet ween gear face and stop plate must be 0 10 7 0 15 mm Fit pinion 9 on crankshaft torquing bolt to 2 0 Kgm Assemble housing 11 on engine case cover inserting it...

Page 29: ...e remove bearings 0 017 Shaft diameter must be 25 0 008 and is net te be ground_ Clutch disk must be free from scores or cracks Disk thick ness must be 3 2 80 mm Thickness of friction materiai is 1 0 mrn on both sides Replace clutch disk if friction materiai thickness i less than 0 3 mm on both sides Note lf springs are damaged or have lost elasticity replace clutch device 8 Assembly Fix housing 3...

Page 30: ... play is excessive or if balls and ball races are demaged Use pullers 7271 3595 28 7070 3595 26 to remove bearings Shaft diamete must be 29 99 30 00 mm and is not to be ground Centrifugai unit housing must have a smooth surface free from projecting burrs and roughness Housing diameter is 100 0 100 1 mm Out of round limi t i 0 05 mm Fig 92 External face of centrifugai unit must not be rough and sho...

Page 31: ...overhaul test may last 90 minutes Start the engine and gradually open choke valve Far engines operating on kerosene fuel start engine on gasoline and warm up far approximate y 2 minutes before turning shut off valve to kerosene feeding position Set and keep engine speed at 2 000 R P M for 10 minutes Accelerate engine repeatedly to ascertain that throttle valve and linkages work smoothly Never oper...

Page 32: ...TTING OF MAXIMUM SPEED Accelerate engine fully and check that maximum idle speed is 3750 è 3800 RPM 2550 2600 RPM for IM250 engines for IM251 engines Adjust screw B Fig 97 accordingly to set maximum speed to above values and tighten its lock nut RUN IN During fìrst 10 hrs of engine operation apply load progressively without exceeding 70 of maximum rated power Note Mentioned adjustement is valid fo...

Page 33: ...e Wrap engine in a plastic sheet Store engine in a dry piace possibly off the ground and away from high power lines Permanent protection over 6 months After procedure as above has been followed we recommend taking further precautions namely Treat rnoving parts with anti rust oil with MIL L 21260 P10 grade 2 SAE 30 characteristics such as ESSO RUST BAN 339 or Valvoline Tectyl 873 Turn engine and dr...

Page 34: ...ine Operation Sloping sense Discontinuous Continuous Longitudinal 4011 35 Transversal FLYWHEEL DYNAMIC MOMENTUM The flywheel dynamic momentum is 1200 Kgcm2 EXHAUST Exhaust back pressure depends on muffler restriction Ma ximum permissible back pressure must be 60 mm of mercury column taken on manifold between flange and muffler END THRUST ON POWER TAKE OFF End thrust in both directions must not exc...

Page 35: ...RE KRAFTABNAHMEN UNO FLANSCHE O UiO 37 su SERIE IM EXTENSION A3 21 11 11 IOU LI 96 EXTENSION 4SAE MANUEL D ATELIER WORKSHOP MANUAL WERKSTATTHANDBUCH EXTENSION EXTENSION 4 a 4 A 1IO 11 0 EXTENSION 9 SAE L_J EXTENSION SA 1 n 1os2 2s hl lA 1197 100 l 100 1 L tj EXTENSION a3 B S 1 O I I EXTENSION 7 SAE 617 10 ht 1S I E 135 2 514 65 t l 950 100 2 37 ...

Page 36: ...nt Elektrische AusrLlstung lnstallation démarreur et alternateur Starter mo tor a ternator Anlage mit Anlassmotor und Dreh Stromgenerator Installation avec dynastart Starter generator An lage mit Lichtanlasser lnstallations éclairage Lighting alternator Licht Anlage mit Drehstromgenerator MONTAGE ET MISE AU POINT ASSEMBLY AND TUNING ZUSAMMENBAU UND EINSTELLUNG VI lntroduction Einleitung Bati Crank...

Page 37: ... I n intermotorS JlO la LOMBARDINlcompanyl liW 02100 RIETI ITALY Casella Postale 107 Tel 0746 72 041 intermotor Telex 612595 lmotor Mod 334 700 I 1 84 ...

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