1980 SKODA 120 LS low oil pressure

Worrring
lights:
5 -
left-hond direction indicotors, green
6 -
oil pressure,
red
7 -
right-hond direction indicotors, green
8 -
broke system, red
9 -
chorging, red
10 -
fuel reserve, omber
11 -
high beom, blue
The thermometer indicotes the temperoture
of the coolont with the ignition switched on.
The optimum operoting temperoture ronge is
from 75 to 105oC. In
SfOon 105 S, this
ronge
is identified by
the green
zone of the scole.
The fuel gouge
indicotes the level
of the fuel
with the ignition switched on. The scole is
provided with divisions 0 -
r/2
-
1, i. e., empty,
holf full,
ond full
tonk.
The driver is worned by the red worning light
when thene ore less thon 5litres of fuel in the
fuel tonk.
The tochometer indicotes the speed (revol-
utions) of the engine. The
speed should
never
rise to the red zone. When chonging the geors,
on increose of speed within the ronge
of the
yellow zone is permissible.
The porking
lights come on when the switch
is thrown to the first
right-hond position.
The
Fig. 1.3/6 Switches -
port I
1 -
Porking light switch ond feeder of heodlomp
dipswitch
2 -
Horn switch, direction indicotor switch,
ond dipswitch
3 -
Switch of ouxiliory (extro)
heodlomps
4 -
Door switch 12
-
unoccupied, green -
fog lomp worning light
included in speciol
extros
13 -
unoccupied, green -
low-beom worning light
included in speciol
extros
14 -
unoccupied, red
switch switches on the heodlomps, toil lights,
ond the licence plote
light.
The heodlights, i. e. driving (high
beom) ond
dipped (low
beom), ore switched on by throw-
ing the switch to the second
right-hond pos-
ition. The switch switches on oll porking
lights
ond the heodlights
in occordonce with the pos-
ition of the switch stem-type lever: centre
position -
dipped lights,
towords the instrument
ponel -
driving lights. When the
driving lights
ore on, the blue worning light glows.
The ouxiliory heodlomps
come on ofter pull.
ing the switch knob, but only while moin
heod-
lomps ore on.
heodlomp flasher storts floshing
when
the switch lever
toword the steering
ring.
horn is sounded by depressing
the lever
the steering wheel shoft.
Fig.1.317 Switches -
port ll ond oshtroy
1 -
Switchbox ond steering lock
2 -
Switch of windscreen wipers ond
wosher
3 -
Heoter switch
4 -
Switch for on odditionol device -
not
stondord fitted
5 -
Disobility worrning light
switch -
not on
SKoDA 105 s
6 -
Heoter control
7 -
Ashtroy
The
pulling
wheel
The
toword
i
I
L 12

Lifting
the cor with o
Power iock -
When
r-rsing o service
Power iock, let the
cor rest on
the points
shown in Fi1.1.412.
To tow the cor, hook the towing rope on
to
the brocket under
the cor nose. Threod the pin
through the loop of the rope
ond the brocket
lugs ond secure the pin
with o cotter pin (both
thL pin
ond the cotter pin
ore included in the
cor occessories).
1.5 SPARE WHEEL
AND FUEL TANK
Spore wheel -
After having opened the
lug-
goge boot lid, pull the hondle of the spore
wheel corrier releose
rod.
The corrier is
re-
leosed ond swings
down (speciol equipment of
the cor includes
o sofety lotch behind the
bumper which hos to be pushecl
oside to
releose the corrier
) . After
hoving closed the corrier (by
lifting it),
push the releose lever under
the bumper to the
right os for os it will go.
Fuel tonk -
The filler neck with cop is in the
reor on the right-hond
side of the cor- lt con
be locked ond unlocked by meons of
the re'
spective key.
1.6 STARTING THE
ENGINE AND CHECKING
ITS CORRECT RUNNING
1. Moke sure thot the geor
lever is in its
neutrol position,
switch on the ignition (pos-
ition I on the switch box) ond wotch the
coming on of the oil pressure ond chorging
worning lights, i.
e. check the function of the
olternotor -
see the informotion in porogroph
4.
Prepore the engine
to its temperoture:
- Storting from cold in
the occelerotor pedol
- Storting from cold in
the occelerotor pedol
choke for
storting occording
winter -
do not touch
ond use the full choke
summer -
do not touch
ond use only holf of the
Fig. 1.5/1 Hondle ot
Rod (f ronr obove )Spcre
Wheel Lock
crnrl Safety Lotch -
Storting o wormed-up engine -
depress the
occelerotor pedol
slowly to tlre
toe-boord, do
not touch the choke
2. Depress the clutch pedol
(odvisoble
in
summer, necessory in
winter) ond stort
the
engine by turning the ignition key to position
ll.
Let go
of the key os soon os the engine fires
ond releose the occelerotor pedol
{if it hos
been
clepressed).
It the engine ,refuses
to fire, return the key
to the position "0"
ond rePeot the
storting
Pro-
cedure. lf the engine is wormed up, depress the
occelerotor pedol
to obout one third of its totol
trovel. lf the cold engine stolls even
ofter the
second ond third storting ottemPt, enrich the
storting mixture by quickly
depressing the
oc-
celerotor pedol
once or twice to holf of its
trovel during the next storting ottemPt.
Never let tlre storter motor run for more
thon
obout 5 seconds. Woit
some 5 seconds before
repeoting the storting.
Fuel is injected
by every quick
depression of
the occelerotor pedol
ond enriches the mixture
so thot it is difficult to ignite. lf the engine
is flooded, stort
it
with o fully depressed oc-
celerotor pedol.
3. Increose the engine speed corefully while
releosing the clutch pedol. lf the
engine shows
signs of stolling, depress
ogoin the clutch
pedol.
Relecse
L.ever
Fi.1.5t2 Fuel Tcrtrk Filler
Neck
16

metre), ond the
relotion of 1
kpm :9.806
Nm is'
opplicoble. When opplied to tightening
torques
of bolts ond nuts, use the relotion
10 Nm :
: 1 kpm.
d) The unit of power (output) tW'
(wott)
reploces the former "h.p."
(horsepower) ond
the relotion
of t h. p.:
735.499 W is opplicoble.
For procticol purposes,
o multiple of kW (kilo-
wott :
1,000 wotts) is used, i. e., t h. p. :
:0.736 kW.
e) The
unit of pressure "Po"
(poscol) or, in
proctice, MPo (megoposcol :
1,000,000 poscols)
or kPo (kiloposcol :
1,000 poscols)
reploces the
former "bor"
ond "kglcmz",
ond the following
relation is opplicoble: 1 MPo: 10 bors :1O.2
kg/cm2 (kp/cm2).
For current meosuring
of tyre
pressure etc., use the relotion: 100 kPo :
1 bor:
:1kglcm2 (kp/cm,) :1
otm.
1.10 GENERAL INSTRUCTIONS
With the exception of o few
speciol pro-
cedures or ossembly techniques
mentioned in
the respective section of
this monuol,
every
removol ond refitting (disossembly
ond re-
ossembly) should be governed
by the following
generol principles:
o) Use suitoble tools ond especiolly tubulor
box sponners which couse the leost domoge
to nuts ond bolt heods.
b) During disossembly note corefully how
the ports
hove been ossembled. This knowledge
is involuoble for correct reossembly.
c) Cleon ports
in trichloroethylene or tech-
nicol petrol.
They do not contoin substonces
(esoeciolly leod) which horm
the skin os motor
petrol does. Current bronds of seoling com-
pounds con be removed with denoturoted
ol-
cohol or scroped off. For o speciol
seoling
compound see the note ot the end of this
chopter.
Avoid contominotion of self-lubricoting
metol
beorings with ony degreosing
ogent os this
would unfovourobly offect their self-lubricoting
properties.
Cleon ports
of the broke ond clutch hydroulic
system with olcohor.
d) Lubricote
oll ports
moving on or in
eoch
other before their ossembly. Operoting lubri-
conts do not spreod eosily on dry surfoces,
the
ports ore not properly
lubricoted, ond friction
oreos ore opt to get
domoged. Coot the os-
sembled ports with the lubricont which is used
to lubricote them in operotion. When lubricoted
with oil, dip
the ports
in motor oil, the f luidity of which mokes
it
especiolly suitoble for
this
purpose. Use greoses
ond hydroulic f luid bronds
specified in the Toble
of Recommended Lubri-
conts.
e) Use new cotter pins
ond metol lock
woshers if you
ore not convinced of the perfect
condition of the old ones which could breok
ond leove the joints
unsecured. Moreover, there
is o risk
of the broken ports
domoging other
functionol ports.
f) Cleon new ontifriction beorings (boll,
rol-
ler, ond topered roller beorings) of preserving
greose using kerosene.
Preserving greose is not
suitoble for lubricotion ond it mixes bodly with
I ubriconts.
g) Some of the joints
hove to be tightened
with o moximum occurocy to the specified
tor-
ques listed in the previous
chopter.
h ) 'Ihe
permissible rototion unbolonce is spe-
cified for some of
the rototing ports,
usuolly in
gcm (gromcentimetres). A well boloqced port
con be stopped in
ony position
if it is
instolled
so thot no rototion resistonce
octs on it. With
the exception of dynomic boloncing, the ports
ore usuolly tested on on ouxiliory shoft ploced
on the
edges. The
unbolonced port
moves from
the deflected position
with its heoviest (i.
e.
unbolonced) port
downword. The
volue of un-
bolonce con be determined
when fostening
o weight corresponding to the permissible
un-
bolonce to the opposite side
of the unbolonced
port. lf the port
does not move when deflected
or if it moves with this weight downword; the
unbolonce is within the recommended limits.
The weight of the testing weight sholl be
de-
termined by dividing the volue of the permis-
sible unbolonce by the distonce of the weight
from the rototion
centre of the port.
i) Even slightly domoged seols ond pockings
must be reploced with new ones
Note: In the foctory,
the speciol seoling
compound
of the "Velvonton
C" brond is used for seoling
the engine reor
cover on the cylinder block, the
moting surfoces of the georbox housing holves,
ond the guide
of the clutch releose beoring.
This seoling compound is mode
on the bose
of o polyurethone
plostic ond it
corresponds to
"Hykemor", "Reineplost", "Curil
K" ond similor
compounds. lt con be removed from the ports
by scroping ond woshing with ocetone, butyl-
ocetone or chlorinoted solvents, for exomple
chloroform (trichloromethone)
ond corbon tetro-
ch loride.
24

2.2-2.3
threods. Fill the etrgine with oil ond the cooling
systenr with on ontifreeze, ond
bleed them.
2.3 REASSEMBLING THE ENGINE
The reossembly procedure depends
on the
extent to which the engine hos been
dis-
rnontled. For better understonditrg, o
reossembly
of o conrpletely disnrontled
engine is described
in the following
porogrophs.
lnspection of
Cylinder Block
1. Clomp the thoroughly cleoned
cylinder
block into the MP 9-101 stond with the engine
corrier type MP 1-101 ond check it for complete-
ness -
see Chopter 2.6. Fit the
block with its
lugs on the engine corrier pins
ond use the side
bolt for ltolding it down.
DK 1188
Fig.2311- Cylinder Block Fostened on the
Assenrbly Stond by lVleons of the MP 1-10-l
Corrier
2. Rernove the pressure
relief volve, moke
sure thot the boll contoct {oces ore cleon,
ond
refit the cleoned volve. Forr
f itting o new volve
see Chopter 2.6.
3. Remove the cronkshoft beoring
covers ond
tlre i;ylinder block reor cover.
To Refit the Cronkshoft
4. Force the beoring shell lrolves with the
fingers into the cronkshoft beoring bores so thot
the shell lip snops home into the slot (cut-out)
in the block ond so thot the shells do not pro'
trude over the beoring surfoces for the beoring
covers, ond lubricote them with engine oil. Be
r;ure to fit shells motching the cronkshoft
i":urnols -
see Chopter 2.7.
5. Slip the oiled guide
ring on the cronkshcft
"vith oil grooves
pointing
toword the cronkshoft
'.veb ond {it the cronkshoft with the pressed-on
boll beoring (see
Chopter 2.7)
into the shell. 6.
Inscrt the
beoring shell
holf ir-rto
the cover
of the beoring No.-l
os described in
porogroph
4,
ond fit the cover with the
recess for the guide
ring turned outword. Proceeding from
the front
of lhe block, slip
on the next guide ring with
the oil grooves pointing
owoy from the block so
thot itJ
lip engoges ogoin into
the slot in the
cover. Coot the ring
with oil ond slip on the
thrust ring. Fit the MP -1'112
thrust collor on the
cronkshofi ond
tighten the
beoring slightly
using the belt
PrrlleY bolt.
7. Instoll the next
two beorirrg covers
corl'l'
plete with beoring shells
ond lightly
tighten l.he
cover nuts.
Press the cork
seol
into the
reo'r
cover moking
sure thot it
f its the groove
snugly
ond slightly bverlops the lower
seoting surfoce'
Before titting the cork seols,
compress them
for
o while in o vice to distort them. Insert the
distorted seols in the grooves
or gops between
the cover qnd
the cylinder block
where they
will expond onci provide
for perfect seoling.
lnsert tob woshers under
the nuts of the
beoring covers
ond while tightening the rruts
check their correct position so os
to enoble
o subsequent correct locking
of the nuts.
Fig.2.312 -
Meosuring Cronkshoft Ploy
1 -
Thrust collor, type
MP 1 112
2 -
Diol indicotor in o
speciolly mode yoke
8. Rotote the cronkshoft severol times ond
using o mollet top the covers ond both shoft
ends to ensure o correct bedding
of the covers
ond cronkshoft guide rings.
9. Tighten the belt pulley nut
to clomp the
thrust ring, ond
rotote ond force
off
the cronk-
shoft to
check its ploy. The
cronkshoft must
be
free to rotote but
without ony
noticeoble ploy.
lf there is o noticeoble ploy, recheck
its volue
ond odiust it by replocing the guide ring with
o new one. The
moximum ploy
should not ex-
ceed 0.10 mm, the recommended minimum ploy
being 0.04 mm. 10.
F
speciol
end onr Drive
suchr o
be turnr
cover. I
ever, tf
the cyl
speciol note in
11. Ti
the tigh
in the
covers. hoving
does no
must ro
Then lo,
woshers
ond nut
To Refil
12. R
greose i
it with i
o flywhr
engine,
with rec
under tt
Chopter
bending
shoft og
powl ins
For flyw
Fig.2.3l3
Using thr
Screw
holes, for
con be ur
further o1
the hondr
30

ilil
ll
I
Z,l
spring woshers under the pump
fostening nuts.
36. lnstoll the oil filter -
see Oil Filter in
Chopter 15.3.
37. Bolt the brocket ond the reloy lever
of the
occelerotor linkoge to the intoke monifold, Use
spring woshers to lock the bolts in position.
38. Locote the corburettor gosket, sheet
guord, onother gosket,
the insuloting wosher,
ond o third gosket (oltogether
three goskets
of
the some type) on the intoke monifold inlet
socket, instoll the corburettor,
ond tighten
it
down with nuts.
On 105 ond 120 l- engines, the sheet guord
must be fitted to the intoke monifold inlet
socket with o throttling spider, while 120 LS
engines must hove the possoge
unobstructed.
39. Smeor the boll pins
of the linkoge
ond
corburettor lever with greose
contoining molyb-
denum disulphide
ond mount on them the oc-
celerotor link (tie-rod).
Hold the link in pliers
ond slip securing clips over the heods.
Hook o spring on the shonk of the reloy
link-
oge boll pin
ond on the rib of the forehousing
on the corburettor.
40. Screw down the vocuum
control pipe
on
the corburettor (using
double-sided seoling
rings) ond slip on the rubber
hose connecting
the pipe
with the distributor vocuum control
unit. Secure the pipe
by bending the clip under
the nut of the intoke ond exhoust monifold.
To Refit Alternotor
41. Attoch the olternotor
brocket to the side
of the cylinder block while putting
ploin
woshers under
the nuts. Mount the olternotor
holder together with the engine mounting lug
on the bolt of the timing geor
cover ond the
front lug of the cylinder block.
Use self-locking
nuts for the bolts f ostening the olternotor
holder. Lock
the lower bolt of the lug by meons
of o spring wosher
ond nut. Using onother bolt,
bolt together the lug ond the brocket. lnsert
the tie-bolt from
the side
of the lug, slip on
o ploin
wosher ond tighten the nut. Fit the
short-circuit strip on the bolt ond lock it in
o position
porollel
with the olternotor brocket
by screwing
down the respective nut with
o ploin
wosher.
42. Put the olternotor into the holder,
ttrreod
in the bolt, ond screw down the nut with o ploin
wosher without tightening. Without tightening
the self-locking
nut, bolt the strut into the
brocket on the cylinder heod. Swing the olter-
notor toword the engine, fit
the V-belt ond,
while tensioning it, connect the olternotor with
the strut using o bolt, spring wosher ond nut.
At the some time, tighten the nut of the bolt
holding down the olternotor
in the
holder ond
the nut of the bolt connecting the strut with
the holder. For the belt slock odiustment see
Chopter 15.3. 43.
Fosten the second
engine mounting lug
using nuts with spring woshers.
To Fit Cylinder Heod, Air
Cleoner,
ond Sporking Plugs
44. Fit the cylinder heod
with cemented.on
gosket on the cylinder block ofter hoving slip-
ped o seoling ring ond o wosher on eoch bolt,
the some os in the cose of the push-rod
cover.
In oddition, fit the fuel pipe
holder on the reor
bolt ond hold it down by slightly tightening the
nut.
45. Fit the oir cleoner in position
ond fosten
it to the corburettor with o bolt using o seoling
ring ond wosher. Put o spring wosher
under the
nut on the brocket
ond screw down the nut on
the bolt of the cover without ony wosher.
46. Threod the fuel hose through its holder
on the cylinder heod ond use clips to fosten it
to the corburettor ond pump.
Adiust the most
suitoble position of the hose by rototing
the
holder ond then tighten the nut.
47. Attoch hoses connecting the oir cleoner
with the corburettor ond the oil filler neck.
When preporing
the cc for driving in winter,
instoll the winter
oir-intoke tube (hose) -
for
detoiled instructions see Chopter 15.3 "Air
Cleoner -
Winter Operotion".
48. Screw in the sporking plugs
with seoling
iings ond fit the ignition cobles. For the re-
commended types of sporking plugs
see Chopter
13.7.
The outlet on the distributor cop morked with
o notch is intended for
the coble
to cylinder
No. 1. The
remoining outlets ore.to be counted
clockwise ond in direct
order from 1
to 4 ond
the cobles will be connected to sporking plugs
in the order of numbers cost on the cylinder
heod beside the recesses for sporking plugs.
Plug Screws ond Lubricotion
System
Accessories
49. Plug the oil sump with the conicol screw
plug with its
seoling ring. In the cose of on
engine without the oil cooler, plug
the oilwoy
on the timing geor
cover with o screw plug
with o seoling
ring, ond the oilwoy ot the reor
end of the cylinder block with o pressure
switch. lf the socket for screwing down the
pressure switch is missing, instoll o new socket
together with its respective seoling ring.
lf on oil cooler is provided,
hoses ond o press-
ure switch should be
connected to the oilwoys
occording to Chopter 11.9.
Put the oil dipstick
with the f itted rubber ring
in its ploce.
For the type of the dipstick see
Chopter 2.17.
50. Using spring
woshers with the bolts,
screw down the flywheel
guorcl
ofter removing
36

For the
instol lotion of the engine on the test
bench, we indicote the dimensions
of the en'
gine flonge ond flywheel. During broking, the
engine qnd
the engine oil must
be properly
cooled to preclude
exceeding the oPtimum
service conditions, i. e. woter temperoture
ofobout
80 to 90oC, ond oil temperoture of 12O"C
moximum -
see Chopter 2.5,
porogroph 51.
Engine Lubricotion
The inner lubricoting oil distribution system
is shown in Fig.2.5/5.
6 DK .r5+9 2.6
cYL
The cyl
mochined
the cronl
ports, forr
ore mode
B locks fo
72 mm di
I i ners.
Oilwoys, I
o) Befo
o new cyl
ossembled
blow thror"
b) Coot
pound or p
the oilwoy
c) Likev
into the e
pound or p,
of the
cyli
one (of
lo
limits indi
Ports) to er
d) Tighte
ot cylinder
under it.
e) Foster
the cop of
Fosten the
with o bolt
Fig.2.611 ond
1 -
choin gre
plug, 3 -
iniel
relief volve,
with cop, 6 -
inlet from o
ptug, I
9
8
7
5t
Fig.2.515 -
Engine Lubricotion Diognom
Skodo 120 LS
engine hos,
in oddition, on oil cooler incorporoted between the punrp
delivery
broncir on the timing geor
cover ond the moin oilwoy (see
Fi9.11.9)
srlctionstroiner,2-pump,3-pressurereliefvolve,4-moinoilwoy,5-oil filter,6-by-poss
hole, 7- oil pressure
switch, 8-pulsotingchomber, 9- rocker orms, 10-connecting rod
splosh hole, 11 -
choin splosh screw
4
2
4 t-
oil I
?
?
I
;
t

The rocker-shqft
support hos o poper
seol
preventing leokoge of the oil fed from the cyl-
inder block to the rockers vio the support. lf
o reody-mode seol (gosket
) is not ovoiloble,
moke it yourself
using poper
0.1 mm thick.
A thicker seol
is unpermissible os it
would
couse c distortion of the rocker shoft. The hole
in the seol
must coincide with the oil hole
of
the rocker.
Apply the seol
ond ref it the
exhoust ond in-
toke monifolds. For detoils see
Chopter 2.3.
porogroph 30.
6. Reinstoll the thernrostotic temoeroture
control cosing with its gosket
ond do not forget
to put
spring woshers under the nuts.
Note: When reossembling
the cylinder heqd
of on engine removed
from the cor, it is odvis-
oble to proceed
with the
iobs os
per
porogroph
5 ond 6 with the cylinder heod refitted
on the
engine to focilitote
the tosk.
lf the cylinder heod gosket
hos been reploced
with o new one, invite the customer to bring in
the cor ofter
trqvelling 500
to 1,000 kilometres
for o retightening of the cylinder heod ond
odiusting of the volve cleoronce. 3. To ensure o leokproof
cond ition of the
volves, grind
them in
with their seots
in the
cylinder heod.
Volve GuideS The volve guides
ore formed directly by the
cylinder heod motericl. lf reconditioning
is
necessqry, rebore the guide
hole ond press-fit
o bush.
Volve guide bushes ore not ovoiloble os
sporre ports. They
con be mode
individuolly oc-
cording to the following drowing. The
required
moteriol is grey
cost iron of 200
N/mmz (2O
kpl
mm2) tensile strength, in
Czechoslovokio cost
iron to specificotions of theCzechoslovokSton-
dord CSN 422421.
Hoving press-fitted
the bush, correct ony
shrinkoge of the inside diometer ond, to motch
the new guides, rrecondition
the volve seots
ond grind-in
the volves.
DK 1+J6 Fig.2.16l
To Recon
These
volves fo
groph 3),
new volvt
Use o
conicol sr
with its r
1. Che
necessory
volves. F
shonk of,
eter, ond
will result
ing in ocr
seot widtl
Check 1
occordinq
Coot the"s
volve in tl
troces of
centre of t
2. Coot 1
volve with
of oil with
volve into
seot ond
1
severof tin
onother po
round the I
volve ond
grinding-in
the volve
c
grey. Use
down the v
Fi1.2.1613
-
Reconditioning Cylinder Heod
for Fitting Volve Guide Bush
Seoling of
Cylinder Heod
As o seporote unit or forming
o unit with
the cylinder block,
the cylinder heod
must be
seoled ogoinst leokoge
of goses
ond woter, i.e.
it must be gos-
ond wotertight.
1. When replocing
some of the bolts pro-
truding into the woter
iocket, seol
them
with
point. The woter
iocket of the
cylinder
heod
must be leckproof
when tested with woter
under c pressure
of 0.5 Mpo (5
kg/cm2).
2. lf it is necessory
to restore the flotness
of t-he cylinder heod
moting surfoce,
,egiind
the
surfcce only to the leost possible
exte-nt so os
not to increose
the engine
compression rotio.Valve
guide
tolerances
Guide 7.94 -
HB +
O.O22
o.oo mm
lnlet Valve 7.94 -
F7
t 9 9?q .n-
+ 0.013
0.025
56 Fi1.2.1614
-
Volve Guide Bush x
1Tr9

d)
e) f) choke
plunger
sticking in its
bottom
position storting worm engine
too high fuel level in floot chomber
incorrectly odiusted
idle run unstick
the plunger
or reploce it with
o new one
odjust the
floot
odiust idle
run correctlY
2.2O FUEL PUMP
Technicol DescriPtion
The model JIKOV MF 3407 fuel pump
is of
the diophrogm ond
lever type, controlled by the
round disc of the comshoft. The suction
motion
of the diophrogm is octuoted by the
lever, the
dischorge motion by the spring of
the dio-
phrogm. Fuel flows through o stroiner, o mud
trop, ond the suction volve to the delivery
volve. A priming lever is provided
for hond
priming of the fuel. The moving mechonism
is
lubricoted with oil
sploshed from the cylinder
block. Stroke of the driving disk 4
mm
Suction heod 1.5
mm
Deliveryheod. 2mm
Pump dischorge ot 2,000 strokes
per minute ond free outflowwithout
counter-pressure 30
ltrs/hr.
Mointenonce, Repoirs, Disossembly
ond Reossembly
For routine
mointenonce (cleoning
of the
mud-trop screen) see Chopter 15.3. After hoving
operoted the hond-priming lever lift it
till it
engoges sofely in its locked position.
ln the cose of o defect, inspect the diophrogm
ond check the volves for leokoge. After hoving
removed the pump
from the engine, remove the
mud trop, seporote the upper port
from the
lower port,
ond remove two screws, holding
down the thrust plote,
to lift owoy the volves.
Swill oll ports
in petrol
ond blow off with com'
pressed oir. Reploce domoged ports
with new
ones. lf necessory, remove the diophrogm from the
octuoting lever in
the lower port
of the fuel
pump (its
monufocturer recommends the dio-
phrogm to be reploced ofter obout 50,000 kilo-
rnetres with o new
one). Do not stretch the
spring of the diophrogm ond do not olter its
compression force chorocteristic in ony woy.
Do not forget to put
fibre pocking rings
underthe
volves
when reossembling the
fuel
PumP.
Put o spocer ring under the suction volve (close
to the mud trop). Fig.2.2Ol1 shows
the pos-
itions of volves ond the holding-down thrust
plote. Put the spring
of the diophrogm into
the
lower port
oi the pump
ond engoge the pin
ot
the diophrogm with the octuoting lever. Oper-
ote the hond lever
to compress the dioPhrogm
oncl hold it in position by inserting o
rod of 4.5
to 5 mm diorneter (for
exomple the
shonk of
o drill, etc.) between the octuoting lever
ond
the woll of the pump
lower
Port.
Now bolt both pump
ports
together so thot
the mud trop is on the
right-hond side when
viewing the pump from obove
ond the fostening
flonge from the front. Use spring
woshers
under the clomping bolts.
Fig.2.2011 -
Section Through
Fuel Pump
lf it is necessory to verify
the dischorge of
the pump
by o test, note the following require'
mentswhich the pump
must meet otl80strokes
per minute:
o) 15 ltrs/hr. ot f ree outf low without
fuel
counterpressure
b) minimum pressure
of 0.018 MPo (1.8
m of
woter column) ot
o zero off'toke of fuel
c) o dry pump
must drow fuel from o
depth of
1.5 m in 16 seconds.
Fuel Pump Defects ond Their Removol
1. Foulty fuel
supply
o) clogged mud trop
b) domoged diophrogm
2. Fuel pump
does not hold fuel
o) dirty or defective volves cleon it
reploce it
with o new one
wosh them in petrol,
reploce defective
volves with new ones
66