check oil FIAT 500 1961 1.G User Guide

FIG 1 :48 Power plant front support cross-section
FIG 1 :49 Checking the generator and blower drive
belt tension
1 :19 Power plant mountings
The combined power and transmission unit is elastic-
ally mounted on two supports.
The front of the unit rests on a crossmember which is
secured under the car floor through two rubber block
mountings that are bolted to the gearbox casing as
shown in FIG 1 :48. The position of the rubber blocks
on the crossmember is adjustable so that the assembly
can be correctly aligned.
W i t h t h e rear of the unit the engine crankcase is sprung
to the b o d y rear crossmember through an articulated
swinging arm that compresses a coil spring as shown in
FIGS 1 :47 and 1 :49. A rubber bump pad is mounted
inside the spring to give a progressive action.
Whenever the power and transmission unit is being
serviced the condition of the mountings should be
checked and any worn or damaged parts renewed.
1 :20 Adjustment of generator and fan drive belt
The centrifugal oil filter cover/pulley on the crankshaft
transmits the drive through a V-belt to the generator and
centrifugal fan pulley.
32
(b) Engine stalls
1 Check 1, 2, 3, 4, 10, 1 1 , 12, 13, 14 and 15 in (a)
2 Sparking plugs defective or gaps incorrect
3 Retarded ignition 1 Defective coil
2 Faulty distributor capacitor (condenser)
3 Dirty, pitted or incorrectly set contact breaker points
4 Ignition wires loose or insulation faulty
5 Water on sparking plug leads
6 Corrosion of battery terminals or battery discharged
7 Faulty or jammed starter
8 Sparking plug leads wrongly connected
9 Vapour lock in fuel pipes
10 Defective fuel pump
11 Overchoking
12 Underchoking
13 Blocked petrol filter or carburetter jets
14 Leaking valves
15 Sticking valves
16 Valve timing incorrect
17 Ignition timing incorrect
(a) Engine will not start 1 :22 Fault diagnosis
Since its introduction the Fiat new 5 0 0 model has
been continually developed. The main modifications that
have been made are as follows:
1 Heating system safety device
2 Recirculation device for the blow-by gases
3 Cylinder head modified to incorporate item 1
4 Double valve springs fitted
5 Cylinder barrels modified to incorporate item 1
6 Flywheel modified to incorporate new type diaphragm
spring clutch mounting
7 Larger air cleaner container.
Details of these modifications are to be found in the
relevant sections if they necessitate a change in service
overhaul procedure. Other information is to be found in
Technical Data.
1 :21 Modifications
When the V-belt has been correctly adjusted the belt
should sag 13/32 inch under a hand pressure of about 22 lb
as shown in FIG 1 : 4 9.
Should the belt be too slack the generator and
centrifugal fan will not operate at the correct speed
causing overheating and a discharged battery. Also the
belt will slip causing rapid wear of the belt. Conversely
if the belt is too tight excessive loading will be placed
on the generator bearings causing excessive bearing
wear and noisy operation.
To adjust the belt tension proceed as follows:
1 Remove the three nuts ' B ' (see FIG 1 :49) on the
generator pulley and this will split the pulley into two
parts between which are spacer rings.
2 The tension of the belt is increased or decreased by
either reducing or increasing the number of spacers.
3 Place the spacer rings removed from between the
pulley halves on the pulley outer face so that the rings
may be re-inserted when fitting a new belt.
4 Tighten the three nuts to a torque wrench setting of
14.5
lb ft.
Key to Fig 1 :49 A Normal give-in: about 13/32 inch under
a 22 Ib pressure B Nuts securing the pulley halves with
spacer rings

4 Mixture too weak
5 Water in fuel system
6 Petrol tank vent blocked
7 Incorrect valve clearance
(c) Engine idles badly
1 Check 1 and 6 in (b)
2 Air leak at manifold joints
3 Slow-running jet blocked or out of adjustment
4 Air leak in carburetter
5 Over-rich mixture
6 Worn piston rings
7 Worn valve stems or guides
8 Weak exhaust valve springs
(d) Engine misfires
1 Check 1, 2, 3, 4, 5, 8, 10, 13, 14, 1 5, 16, 17 in (a);
2, 3, 4 and 7 in (b)
2 Weak or broken valve springs
(e) Engine overheats
1 Generator and fan drive belt too loose
2 Shutter or thermostat seized in closed position
(f) Compression low
1 Check 14 and 15 in (a), 6 and 7 in (c) and 2 in (d)
2 Worn piston ring grooves
3 Scored or worn cylinder bores
(g) Engine lacks power
1 Check 3, 10, 1 1 , 13, 14, 15, 16 and 17 in (a), 2, 3, 4
and 7 in (b) 6 and 7 in (c) and 2 in (d). Also check (e)
and (f)
2 Leaking joint washers
3 Fouled sparking plugs
4 Automatic centrifugal advance not operating
(h) Burnt valves or seats
1 Check 14 and 15 in (a), 7 in (b) and 2 in (d). Alsocheck (e)
2 Excessive carbon around valve seat and head
(j) Sticking valves
1 Check 2 in (d)
2 Bent valve stem
3 Scored valve stem or guide
4 Incorrect valve clearance
(k) Excessive cylinder wear
1 Check 11 in (a) and see Chapter 4
2 Lack of oil
3 Dirty oil
4 Piston rings gummed up or broken
5 Badly fitting piston rings
6 Connecting rods bent
(l) Excessive oil consumption
1 Check 6 and 7 in (c) and check (k)
2 Ring gaps too wide
3 Oil return holes in piston choked with carbon
4 Scored cylinders
5 Oil level too high
6 External oil leaks
7 Ineffective valve stem oil seals
(m) Crankshaft and connecting rod bearing failure
1 Check 2 in (k)
2 Restricted oilways
3 Worn journals or crank pins
4 Loose bearing caps
5 Extremely low oil pressure
6 Bent connecting rod
(n) High fuel consumption (see Chapter 2)
(o) Engine vibration
1 Loose generator bolts
2 Blower blade assembly out-of-balance
3 Incorrect clearance for rear engine mounting rubber
F50033

1
14,5
7,52 9 48 35
76
FIG 2:15 Float level setting diagram Weber car-
buretter type 26.OC
7.5 = .29 inch 14.5 = .57 inch
Key to Fig 2:15 1 Carburetter cover 2 Cover gasket
3 Needle valve 4 Valve needle 5 Lug 6, 7 Arms
8 Needle ball 9 Float
Idle speed adjustment:
The idling speed is adjusted by movement of the throttle
setscrew and the mixture setscrew. The throttle screw
allows for the adjustment of the throttle opening whereas
the conical mixture setscrew has the purpose of metering
the amount of charge issuing from the idling speed pas-
sage, which will then mix with the air flowing past the
throttle which when correctly set for normal idling speed
should leave a gap between its edges and the throat walls.
This ensures a correct petrol/air ratio best suited to the
engine requirements and smooth operation.
The idling speed should always be adjusted with the
engine running and at its normal operating temperature
by first setting the throttle to its minimum opening by
turning the throttle setscrew so enabling an accurate
adjustment to be made. Then slowly turn the mixture set-
screw either in or out so as to adjust the mixture petrol/air
ratio to the most suitable for the throttle opening, this will
accomplish a fast and steady idling speed which should be
then reduced by closing the throttle opening slightly by
easing back the throttle setscrew. This adjustment should
continue until the best idling speed is obtained.
Adjustment of fuel level in float chamber:
To check and adjust the level of fuel in the carburetter
float chamber proceed as follows:
1 Check that the needle valve 3 (see FIG 2:15) is
screwed tight on its seat.
2 Keep the carburetter cover 1 upright or else the weight
of the float 9 will lower the ball 8 fitted on the needle 4.
F50043
Key to Fig 2:17 1 Filter housing 2 Spring hooks
3 Filter element 4 Cover 5 Air suction pipe, hoses
and clamps 6 Re-circulation pipe for blow-by gases and
oil vapoursFIG 2:17 Removing the air cleaner, 500F, L
2
1 3
4.
6
5
FIG 2:16 Taking out the filter element, 500, 500D AIR CLEANER ELBOW
HOSE
AIR CLEANER BODY
FILTER ELEMENT Check that with the cover held in the vertical position
and the float arm 6 in slight contact with the ball 8 of the
needle 4, the float is .2953 inch away from the cover
w i t h its gasket 2 fitted flat against the cover face.
3 Check that the float level is .5709 inch from the cover
face and if necessary bend the lug 5 to give the required
setting.
4 If the float 9 is not correctly positioned bend the float
arm 7 until the correct adjustment is obtained. Ensure
that the arm 6 is perpendicular to the needle axis and
does not show any rough spots or indentations which
might impair free movement of the needle. Check that
the float 9 moves about its pivot pin.
Every time a new float or needle valve is fitted the above
detailed adjustment operations must be completed to
ensure correct fuel levels.

FIG 2:18Diagram of blow-by gases re-circulation device
Key to Fig 2:181 Head cover 2 Blow-by gases and oil vapours breather valve 3 Oil filler cap4 Strainer
9 Air suction pipe, air cleaner to carburetter 8 Flame trap
13 Exhaust duct 12 Crankcase 7 Carburetter 6 Air cleaner
11 Filter gauze
10 Movable partition 5 PipeEngine 110 F. 000 Engine 120.000
designed to dampen the air intake noise and the carburet-
ter venturi hiss and is so located in the blower conveyor
system so that only clean dry air is drawn into the induc-
tion system.
To ensure complete protection of the engine it is
recommended that the air filter element be replaced every
6000 miles or even earlier if the vehicle is operating in
dusty conditions.
It should be noted that an oversize air cleaner may be
obtained if the vehicle is to be operated in very dusty areas.
Air cleaner—engine 110 F.000:
To remove the air cleaner element, disengage both the
spring hooks 2 as shown in FIG 2:17 and lift away the
cover 4 by turning it inwards together with the hose 5. 2 : 9 Air cleaner (sedan)
The pleated paper air cleaner element is contained in a
casing housed in a recess of one of the silencing chambers
provided in the blower conveyor as shown in FIG 2:16.
The air cleaner is connected to the carburetter by means of
a specially shaped hose. The silencing chamber is
44For full instruction refer to Section 2 :6. Carburetter cleaning:See Section 2 :6 for full check details. Throttle valve components:
Engine 110 F. 000

Air cleaner—station wagon:
A pleated paper air cleaner element is housed in a
special air intake chamber connected to the front of the
engine air cooling cowling (see FIG 4 : 2) . This chamber
will be seen located towards the rear of t h e power unit
compartment. Remove the retaining wing nut, lift off the
lid and the element can be withdrawn by lifting upwards.
2:10 Blow-by-gases recirculation device
Engine 110 F.000
All the oil vapours and blow-by-gases that are formed
in the engine crankcase are drawn to the cylinder head
cover recess 1 (see FIG 2:18). From here they travel into
the pipe 5 via a breather valve 2 which is firmly attached to
the oil filler cap 3 and the strainer 4 located in the filler
neck. The oil vapours and gases are then d r a w n back into
the duct 9 from the pipe 5 which connects the air cleaner
6 to the carburetter 7. This ensures a complete closed cir-
cuit circulation.
Engine 120.000:
From engine No. 288156 the oil vapours and blow-by-
gases instead of being exhausted to the atmosphere are
conveyed to the air cleaner and from here they are drawn
back into the combustion chambers. To ensure that an
excessive of oil vapour does not pass along the piping
with the blow-by-gases a diaphragm is fitted in the duct
in front of the breather valve 2 (see FIG 2 :18), the dia-
phragm comprising a filter gauze 11 and moveable parti-
tion 10.
It should be noted that the oil vapour strainer 4 (see
FIG 2:18) and the flame trap 8 can easily be removed
from their seating for cleaning or renewal.
2 : 1 1 Fuel tank
The fuel tank is located in the front compartment as
shown in FIG 2:19, it comprises a filler union fitted with a
cap, a fuel reserve supply indicator sender unit and a con-
nection incorporating a filter for the main fuel supply pipes.
To remove the tank proceed as follows:
1 Remove the contents of the front compartment includ-
ing the spare wheel and tool bag.
2 Disconnect the main fuel line at the sender unit and also
disconnect the cable to the fuel reserve supply indicator.
3 Remove the four screws together w i t h the clips that fix
the tank to the body and carefully lift away the fuel tank.
4 Carefully drain the contents of the tank into a clean dry
container of a suitable capacity.
Fuel tank—sedan (110 F.) and station wagon (120):
The fuel tank is arranged in the front compartment as
shown in FIG 2 :20. To remove the fuel tank proceed as
follows:
1 Remove both screws which secure the front ends of the
clamping bands to the dash panel. The screws are
shown by arrows in FIG 2 :20.
Petrol tank cleaning:
The tank must be thoroughly checked for leaks espe-
cially at the joint seams. Should a leak be found it is
F50045
advisable for a garage to attend to this as it is very dange-
rous to apply heat to a petrol tank without first taking strict
precautions and a garage will be in a better position to do
this. To clean the tank interior, remove the drain plug and
spray in a jet of air or petrol so that all sediment and dirt
deposits can be loosened. Then vigorously shake the tank.
Flush the tank w i t h petrol and blow the tank dry. Repeat
this procedure until the tank is clean. Refit the drain plug.
Whilst the petrol tank is away from the car it is advisable
to disconnect the fuel feed pipes at the pump and the
carburetter and ensure that these are clear by using an air
jet to one end of the pipe.
Key t o Fig 2 :20
Note Arrows point to fuel tank clamping band screws vent valve
indicator tank unit1 Fuel tank2 Filler cap with
3 Fuel suction pipe and reserve supply
4 Tank clamping bands
FIG 2:20 Location of the fuel tank in front compart-
ment, 500F, L FIG 2:19 Fuel tank in front compartment. The fuel
reserve supply indicator (red light) glows when fuel
amount in tank is less than .8 to 1.1 Imp galls, or 5 litre FUEL TANK
FUEL LINE TO PUMP
FUEL GAUGE CABLE

FIG 3 : 1 Ignition system wiring diagram
BATTERY
SWITCHBREAKER COIL
SPARK PLUG
CONDENSER
FIG 3 : 2 Ignition distributor in place on engine with
cap lifted offCURRENT CONTACT
TO SPARK PLUG
BREAKER A R M
STATIONARY
CONTACT
CARRIER
ADJUSTING
SCREW
CONTACT POINTS HIGH TENSION)
CARBON CONTACT
3 : 3 Routine maintenance
Refer to FIG 3: 2 and remove the distributor cap and lift
off the rotor arm. Lubricate the cam spindle felt pad using
Fiat VS oil. There is provision for the oil to make its way
downwards. Squirt a few drops of oil into the distributor
shaft lubrication fitting, the location being shown in FIG
3:3 Smear a little grease on the cam and a small drop of
oil to the contact breaker point pivot.
Adjusting the contact breaker points:
Refer to FIG 3 : 2 and slacken the stationary contact
carrier adjusting screw. Slowly rotate the engine until one
one of the t w o cams has opened the points to the fullest
48
extent so that the gap is measured at the position of the
maximum opening. Reset the gap to a correct clearance of
.0185 to .0209 inch and tighten the contact carrier screw.
Cleaning the contact points:
If the contact points are dirty or pitted they must be
cleaned by polishing them with a fine carborundum stone
taking very great care to ensure that the contact faces are
flat and square. Afterwards wipe away all dust with a cloth
moistened in petrol. The contacts may be removed from
the distributor body to assist refacing and cleaning refer-
ring to Section 3:5. If the moving contact is removed
from its pivot, check that its operation is not sluggish. If it is
tight, polish the pivot pin with a strip of fine emery cloth,
clean off all dust and apply a tiny spot of oil to the top of
the pivot pin. If a spring testing gauge is available the
contact breaker spring should have a tension of 16.8± 1.8
oz. measured at the points.
3 :4 Ignition faults
If the engine runs unevenly set it to idle at a fast speed.
Taking care not to touch any metal part of the sparking
plug leads, pull up the insulator sleeve and short each
plug in turn, using a screwdriver with an insulated handle.
Connect the screwdriver blade between the plug top and
the cylinder head. Shorting a plug which is firing properly
will make the engine uneven running more pronounced.
Shorting a plug in a cylinder which is not firing will make
no difference.
Having located the
faulty cylinder, stop the engine and
remove the plug lead. Start the engine and hold the lead
carefully to avoid shocks so that the metal end is about
3/16 inch away from the cylinder head. A strong regular
spark shows that the fault might be with the sparking plug.
Remove and clean it according to the instructions in
Section 3 :8. Alternatively substitute it with a new plug.
If the spark is weak and irregular, check that the lead is
not perished or cracked. If it appears to be defective,
renew it and try another test. If there is no improvement,
remove the distributor cap and wipe the inside clean and
dry. Check the carbon brush located as shown in FIG 3 : 2 .
It should protrude from the cap moulding and be free to
move against the pressure of the internal spring. Examine
the surface inside the cap for signs of 'tracking' which can
be seen as a thin black line between the electrodes or to
some metal part in contact with the cap. This is caused by
sparking, and the only cure is to fit a new cap.
Testing the low-tension circuit:
Before carrying out electrical tests, confirm that the
contact breaker points are clean and correctly set, then
proceed as follows:
1 Disconnect the black low-tension cable from the
ignition coil and from the side of the distributor.
Connect a test lamp between the t w o terminals. Turn
the engine over slowly. If the lamp lights when the
contacts close and goes out when they open, the
low-tension circuit is in order. If the lamp fails to light
the contacts are dirty or there is a break or loose con-
nection in the low-tension wiring.
2 If the fault lies in the
low-tension circuit, switch on
the ignition and turn the crankshaft until the contact
breaker points are fully open. Refer to the wiring
diagram in Technical Data and check the circuit with

FIG 3 : 4 Use of fixture Ap.5030/1 to check ignition
timing
Reassembly is the reverse procedure to dismantling but
the following points should be noted:
1 Lubricate the parts of the centrifugal advance mecha-
nism, the drive spindle and the part of the shaft which
accepts the cam w i t h Fiat VS oil.
2 Ensure that upon reassembly the slot in the rotor arm
housing matches the distributor driving dog. Lubricate
the felt pad in the rotor arm housing.
3 Fit the distributor back onto its support gently rotating
the rotor arm so that the drive dog engages w i t h the
drive shaft mating flange. Provided the crankshaft has
not been turned the rotor arm should finish up pointing
to No. 1 cylinder segment in the distributor cap. Tighten
the distributor retaining nut, refit the distributor cap and
leads to the spark plugs and the LT lead to distributor
body terminal.
4 Add a few drops of oil to the distributor shaft lubrication
fitting (see FIG 3:3).
3 : 6 Removing and dismantling distributor
(station wagon)
The distributor is located towards the top rear of t h e
engine and is bolted direct onto the crankcase rear cover as
shown in FIG 1 : 2 . It is driven direct by a gear in mesh w i t h
a corresponding gear on the camshaft. The basic design of
the distributor is the same as that for the sedan and sports
engine, except that the distributor cap has been redesigned,
there is a gear instead of the dog
drive and no distributor
support. To remove and dismantle the distributor proceed
as previously described taking great care about marking
the location of the distributor to rear cover and rotating
the engine until No. 1 cylinder is on compression. This will
ensure that reassembly is straightforward without loss of
ignition timing.
503:7 Timing the ignition
It is necessary to retime the ignition should the distribu-
tor shaft or camshaft have been removed. To retime the
ignition proceed as follows:
1 On the timing sprocket cover fit Fiat tool AP.5030/1 as
shown in FIG 3 : 4. Ensure No. 1 cylinder is on the
compression stroke with both valves closed. Rotate the
crankshaft until the mark on the centrifugal filter cover
lines up w i t h the 10° mark on the fixture. This setting
corresponds to a 10° static advance BTDC.
2 Check t h a t the points gap is correctly set between
.018 and .020 inch. Turn the distributor shaft until the
rotor points in the direction of No. 1 segment in the
cap and the points are just opening.
3 Without disturbing the distributor shaft, insert the lower
coupling on its toothed end, install the support and
tighten the locknut. Secure the distributor to the sup-
port using the mounting screw.
To check that the distributor is properly timed to the
engine and the centrifugal automatic advance is operating
correctly giving a
total advance of 18° to 28° respectively
proceed as follows:
1 Connect Fiat timing tester AP.5030 with a 220-volt-
single-phase power outlet fitted with a good earth
connection. It is important that the tester is earthed
before it is allowed to operate. Also ensure that the
tester earth terminal is connected to a bare metal part
of the vehicle.
2 Remove No. 1 spark plug lead, insert the strobe light
adapter and reconnect the spark plug lead. Using a
piece of white chalk mark the TDC position on the
centrifugal filter cover.
3 Start the engine and aim the strobe light beam towards
the chalk mark drawn on the centrifugal filter cover.
With the engine running slowly the mark on the centri-
fugal cover must correspond wi th the first white line
on the fixture (10°). Slowly increase the speed of the
engine so operating the automatic advance and the
chalk mark should move counterclockwise until at
maximum speed it reaches the second white mark on
the fixture.
It should be noted that the ignition timing for the model
500 sports engine the static advance is 10°, an automatic
advance of 12° giving a total advance at maximum engine
speed of 2 2 ° .
Should Fiat fixture AP.5030/1 not be available the
advance position may be set as follows:
1 Turn over the
engine until No. 1 piston is on the com-
pression stroke w i t h both valves closed.
2 Rotate the crankshaft clockwise until the reference
mark cast on the centrifugal filter cover is set .5118 to
.5512 inch ahead of the arrow cast on the timing
sprocket cover. This will give a static advance setting
of 10° BTDC.
3 Proceed as directed for ignition distributor timing and
mounting described earlier in this section.
3 : 8 Sparking plugs
The sparking plugs must be regularly inspected, cleaned
and the electrode gap adjusted to a gap of .019 to .023
inch.
The inspection of the deposits on the electrodes is par-
ticularly useful because the colour and type of deposit

indicates the condition inside the combustion chamber
and may be used as a guide to engine tuning.
Before the spark plugs are removed b l o w away any
loose dirt from the plug recesses using a compressed air
jet or tyre pump. Store the plugs in the order of removal
ready for inspection.
Examine the gaskets and if they are about half their
thickness they may be used again otherwise they must be
replaced.
Inspect the electrode end of the plugs and note the
type and colour of the deposit. Normally it should be
powdery and range from b r o w n to a greyish tan in colour.
There will also be slight wear of the electrodes and the
general effect described is one which comes from mixed
periods of high-speed and low-speed driving. Cleaning
and resetting the gap is all that will be necessary.
If the deposits are white or yellowish they indicate long
periods of constant-speed driving or much low-speed
city driving. Again, the treatment is straightforward.
Dry, black, fluffy deposits are usually the result of
running with too rich a mixture. Incomplete combustion
of the petrol air charge may also be a cause and this might
be traced to a defect in the ignition system or excessive
idling.
Overheated sparking plugs have a white blistered look
about the centre electrode and the side electrode may be
badly eroded. This may be caused by poor cooling, wrong
ignition timing or sustained high speeds under heavy load.
To clean the sparking plugs effectively they should be
cleaned using an abrasive blasting machine and tested
under pressure once the electrodes have been reset. File
these until they are clean, bright and the faces parallel and
set the gap to .019 to .023 inch. Do not try to bend the
centre electrode.
Before replacing the plugs use a wire brush to clean the
threads taking care that the electrodes are not touched.
Thoroughly clean the spark plug in petrol, and dry using a
compressed air jet or a tyre pump. If difficulty is found in
screwing the plugs into the cylinder head by hand run a
tap d o w n the threads to clear away any carbon. If a tap is
not available use an old sparking plug with crosscuts d o w nthe threads. Finally tighten the plugs to a torque wrench
setting of 18 to 21 Ib ft.
Sparking plug leads:
The spark plug leads and the lead from the coil to the
distributor cap must be regularly checked for cracking of
the insulation and also correct seating in the distributor
cap and coil top. It is recommended that silicone grease is
smeared around the sockets before the leads are replaced
to ensure no moisture may enter causing difficult starting.
3 : 9 The distributor driving spindle (sedan and
sports engine)
If for any reason, the driving spindle has been removed
from its housing in the crankcase, it must be correctly
meshed w i t h the camshaft gear otherwise it
will be impos-
sible to set the ignition timing.
3:10 Fault diagnosis
(a) Engine w i l l not fire
1 Battery discharged
2 Distributor contact points dirty, pitted or maladjusted
3 Distributor cap dirty, cracked or tracking
4 Carbon brush inside distributor cap not touching rotor
5 Faulty cable or loose connection in low-tension circuit
6 Distributor rotor arm cracked
7 Faulty coil
8 Broken contact breaker spring
9 Contact points stuck open
(b) Engine misfires
1 Check 2, 3, 4, and 7 in (a)
2 Weak contact breaker spring
3 High-tension plug and coil leads cracked or perished
4 Sparking plug(s) loose
5 Sparking plug insulation cracked
6 Sparking plug gap incorrectly set
7 Ignition timing too far advanced

OIL DRAIN PLUG COOLING AIR DUCTS
FIG 4 : 3 Oil sump with blower cowling. Arrows indicate
air outlets
BLOWER
SHAFT GENERATOR ARMATURE
VENT TUBE
FIG 4 : 4 Cooling blower mounted on generator shaft
extension
4 : 2 Air outlet thermostat and shutter
Refer to FIGS 4 :1 and 4 :2 where it will be seen that
the thermostat is located on the righthand side of the
engine cowling. The thermostat should start opening the
engine heated air outlet shutter when the temperature of
the air reaches between 158-165°F (178-185°F station
wagon) and the shutter should be in the wide open posi-
tion when the air has reached a temperature of between
178-189°F (196-207°F station wagon).
When the engine cooling air control system is being
inspected or serviced the following points should be
noted:
1 Check that when the shutter is in the closed
position the edge mates perfectly with the cowling
seating.
2 Ensure that the shutter can swivel freely.
3 Check that the initial thermostat movement is
between .0197 to .0394 inch.
4 Generally check the engine cowling for distortion, bad
jbint sealing or cracks.
56
Key to Fig 4 : 6 1 Circular seat i n cylinders 2 Head
ducts 3 Pierced screws
FIG 4 : 6 Diagram of the heating system safety device
(sedan and station wagon) FIG 4 : 5 Location of cooling air outlet thermostat and
shutter
ENGINE COWLING.
THERMOSTAT
LINK
AIR OUTLET SHUTTER
SHUTTER RETURN SPRING
4 : 3 Tension adjustment, thermostat to shutter
link:
The tension may be varied by using the shims which are
located between the upper shank of the thermostat and
the cover shoulder washer. Before any adjustment is made
ensure that the shutter is able to move freely and that the
return spring has not stretched or fractured. Refer to
FIG 4:5 which shows the location of the shutter and the
return spring.

lubricated using Fiat Jota 3 grease.
1 Pressure plate—boss outer faces.
2 Clutch cover—withdrawal lever fulcrum.
3 Withdrawal lever stopnuts—contact face.
4 Withdrawal lever carrier ring — lever contact face.
5 Crankcase end pilot bushing lubricated with Fiat KG.15
grease.
6 Lubricate contact faces of driven plate and clutch shaft.
To install the clutch assembly proceed as follows:
1 Ensure t h a t there is no grease or oil on the faces of the
driven plate or flywheel face and position with the
raised part of the hub towards the transmission unit.
2 Locate Fiat tool A.70085 (diaphragm clutch) or
A . 6 2 0 2 3 (coil spring clutch) or a suitably sized drift,
through the driven plate hub and position in crankshaft
pilot bushing. Gradually tighten the clutch unit
mounting screws working diagonally and finally tighten
to a torque wrench setting of 5.8 to 7.2 Ib ft.
5 : 6 Pilot bushing
Whenever the clutch unit is being renewed or over-
hauled it is essential that the crankshaft pilot bush is
checked for excessive wear or damage. Also check that
FIG 5 : 7 Side sectional view of clutch and throw-out
mechanism - 5 0 0 Sedan (11OF), late Station Wagon. Value
1.5 mm (.059 inch) refers to the clearance to be obtained
through the adjustment of clutch throw-out yoke rod
F50063
The withdrawal mechanism comprises a forked lever
(see FIG 5 : 8), which is located in the clutch housing and 5:7 Withdrawal mechanism
New 500 and 500D models:
the spigot on the bush end is in a good serviceable con-
dition. The maximum clearance between the clutch shaft
spigot and the bush should not be greater than .0059 inch
otherwise the pilot bush must be renewed. To remove the
pilot bush use Fiat puller A.40006/1 /2 or a small universal
internal bush and bearing removal tool.
To fit a new bush use a suitably sized drift and drive the
bush fully home and lubricate well with Fiat KG.15 grease. FIG 5 : 9 Clutch controls and adjusting mechanism LEVER RETURN SPRING
ADJUSTABLETIE R O DCLUTCH RELEASE LEVER NUT A N D JAM NUT
FOR TIE R O D CLUTCH RELEASE BOWDEN FIG 5:8 Clutch throw-out mechanism
CLUTCHSHAFT
LEVER-AND-SHAFT
RELEASE
RELEASETHRUST RING
FORK-TO-THRUSTFASTENERS RING
CARBON
RING
WITHDRAWAL FORKCLUTCH