1980 SKODA 105S check oil

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

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

primory
feed to the distributor coincides with
the connecting line of the
distributor centre
line ond the first cylinder
heod
bolt os
per
Fig.2.3l10. Secure the distributor in this pos-
ition by lightly tightenning the tie-bolt ond
remove the timing geor
cover from the cylinder
block. The used type of distributor is described
in Chopter 13.5.
Fig.2.3l10 -
Position of Distributor on Engine
-l - screw of primory power
feed
2 -
cylinder heod bolt
3 -
index line rnorking the position
of the
distributor ornr when cvlinder No. 1 f ires
24. Coot with oil the moting
surfoces of the
timing geor cover ond the cylinder
block, locote
the cover gosket
on the block,
oil the timing
choin ond the comshott worm geor.
Remove the
f lywheel powl
ond rotote the
cronkshoft through
360o so
os to bring tlre pistons
of the cylinders
No. 1 ond 4 to their TDC position
ogoin. This
position corresponds opproximotely
to the volve
geor position
when the cylinder No. 1 f ires (the
tips of the coms of
cylinder No. 1 ore turned
downword, owoy from
the engine). Lock the
cronkshoft in position by refitting ond tight-
ening the flywheel powl.
25. Turn
the distributor orm in the direction
of the
screw (1) in occordonce with Fig. 2.3110,
hold it down with the
finger in this position,
ond ref it the timing geor
cover on the cylinder
block. By sliding the worm geor
of the distribu-
tor drive into the comshoft worm geor,
the orm
is turned to coincide with the timing
mork for
cylinder No. 1
on the distributor housing. lf
there is no coincidence of the orm ond timing
mork, od just
the position
of the orm by
slightly
rototing the distributor.
lf the
misolignment of the distributor
ornr
ond the timinq
mork of the
cvlinder
No'1 is so greot
thot it connot be corrected
by rototing
the distributor, remove
the timing geor
cover,
rotote the distributor slightly ond repeot
the
entire procedure
of refitting the timing geor
cover. 26. Smeor the protruding
end of the cronk-
shoft ond the outer shoft end (stem)
of the
belt
pulley with oil, f
it the belt pulley,
the nespective
wosher, ond tighten the bolt. Bolt the
PumP
suction stroiner tothe cronkshoft centre beoring
ond use o spring
wosher under the bolt heod.
27. Bolt down the timing geor
cover using
spring woshers ond
cheese-heod bolts
(exclus-
ively) cnd f inolly fosten the timing geor
cover
in such o position
thot the contoct breoker
points open before the crronkshoft with
the con-
necting rod ond piston
hos ottoined the top
deod centre (TDC)
position (see
the lgnition
Timing Toble in Chopter 15.3).
For checking the ignition odvonce, on electric
power supply is required with o bulb connected
in o circuit with the distributor. this
circuit
being interrupted by the oction of the contoct
breoker. An odopted conventionol torch with o
metol
iocket con be
used with odvontoge for this
purpose. Remove the flywheel powl ond
set the re-
quired ignition odvonce by turning the cronk-
shoft with o screw'driver inserted into
the geor
ring ond propped ogoinst the cylinder block
f longe. Rotote the shof t onticlockwise o bit
more thon necessory ond
bock it off so os to
odiust the bocklosh of the timing geors
ond the
distributor drive geors.
oK 6ls
Fi9.2.3111- Lomp for Checking the Opening
of Contoct Breoker Points
-1 - torch complete with dry cell ond bulb
2 -
leod with olligotor clomp
3 -
botterv cell
4 -
torch coo
5 -
contoct spring
6 -
insuloting plote
7 -
electricol-contoct connection of the leod
with the
drv cell Con
using
torch.
the br
slowly
indico
A corr
is not
timing 28.L
beorin
Then f
while
oil sun
the thr
the tyl
see Cl.
shri n ks
of the
woter
move i
ively.
To Fit
Toppetr
25. r
remove
positior
sure thr
cylinder
cylinder nuts. F<
first bo
woteir p
oir clec
finol ti1
2.16.
Ploin
heod bo
which t
woshers
no wosl
heod bo
cy I i nder
the outs
hove to
of the rc
Tighte
broce or,
30. Sc
thermom
into the
cosing o
ofter ho
Use spri
thermost
cooted g
with the
with the
The th
should br
34

2.7.-2.8
Guide Rings Regrinding of the foce of the front
cronkshoft
web results in
on increosed (oxiol) ploy
of the
shoft. Reploce therefore the originol guide
ring with
on oversize one. Oversize guide
rings ore fitted exclusively
to
the regrround loterol
foce of the cronkshoft web.
Stondord size rings
should be olwoys fitted
to
the thrust ring side (next
to the timing geor).
Thrust Ring
lf the thrust ring under the cronkshoft timing
geor (sprocket)
obutting ogoinst the guide
ring is worn to on
extent
which mokes domoge of
the guide
ring likely, reploce it
with o new one
or regrind it.
The moximum permissible
regrinding is, how-
ever, to o thickness of only 3.75 mm.
Cronkshoft Moin Beoring Shells
Fit the cronkshoft moin beorings (shells)
occording to the respective nominol diometer
of the cronkshoft
iounnols. The shells
ore not
provided with o diometer symbol so thot they
hove to be checked for
the respective woll
thickness with o micrometer.
2.8 FLYWHEEL WITH GEAR RING
Boloncing -
Removol ond Refitting
A new flywheel ossembly is o
stoticolly bo-
lonced unit, its moximum permissible residuol
out-of-bolonce weight being '10
gcm. The finol
lf one of the
shells
is worn or domoged, o ll
cronkshoft moin beoring shells must be reploced without foil !
For the respective correlotion of the cronk-
pins ond connecting rod
big-end beorings see
Chopter 2.11. dynomi<
ism shr
sembfed
Thus
sitioq of
shoft be
from o
1
When
rnork on
zero line
ond prol
mork op
cylinder
the rem<
gcm sin
mosses (
concentr
cronksho
holes rot
wheel ir
interf erel
For thi
on the r
sition, i.
cronksho
fore the
When
one or wl
follows:
1. Fit .
residuol o
olly offec
2. The
bolonce r
hos o hig
correctior
once. lt
occording
porogroph
Chopter 1
bending t
To Reploc
Reploce
worn or d,
ring, toke
the interfr
sion). The
prime impr
ossembly
storter mo
The gec
removed b
port pod
cr
MP 1-153. I
ing the ge
it off. The
monufoctut
When ur
front foce
ond drill
o
Fig.2.8l1- Morking
Correct Position of
on Cronkshoft (prior
to removing theFlywheel
f lywheel)
Motching
Cronkshoft Main Beorings with Journols
Nominol cronkshoft mmiournol
diometer Thickness
of beoring
shell woll
mm Toleronce limit
of woll thickness
mm
dio. 55 dio.54.75
dio. 54.50 dio.54.25
dio. 54 stondord
1st regrinding
2nd regrinding
3rd regrinding
4th regrinding 1.497
1.622
1.747
1.872
1.997
-
0.007
44

Nominol
diometer
mm Gudgeon
pin
diometer mIn Pin
bore
in piston
nl
n] Connecting
rod
smoll-end bore
(br-rsh diometer)
mm
20
20.0s 20
-
0.003
20.0s --
0.003 -
0.004
zu - o.o1o
,o 05, 3 3?3 2a
13 33?
,o os
13
33?
Toble
ofMotching GudgeonPins
to Pistons ond
Smoll'end Bushes The
cler
should be
cleoronce
the rings
2.11 COn
The con
o brorrze
b
beoring sh
in the big
Before r
for compli<
weight, ol
ond motch
shoft.
For its
<
ter 2.12.
To Check
Connecti
weight gror
foctory, ligl
yellow poi
Should the
during stor
been fitted
determ ined
remove o c
smoll ond t
the smoll
r
in the
engi
(+2 gr.).
When re
odjust its w
connecting
DK 63:
Fig
'l - boloncing
2 -
numericol
GUDGEON
PIN
Tlre gr-rdgeon pin
is cr slight interference f it in
the piston-
lts cleoronce in the
connecting rod
smoll-end bush is:;pecified in
the Chopter
"Connecting Rocl ".
The steel gudgeon pin
is lrollow ond hos
c rronrinol cl iometer of 20 ntnr,
replocement pitts
l.rovirrg; o nominol dionreter of
20.05 mnr. When
f itting on oversize gudgeon
pin with 20.05 mm
nomincl diometer, the bore
toking the pin must
be reomed to dimerrsions
specif ied irr the re-
spective l-oble.
PISTON RINGS
To ensure their correct function, they must
be f itted in the correct position, they
must hove
no or onlv c minimum cleoronce clong
their
r:ircumference, o smqll
cleoronce in
the gops'
ond tlrey mLrst rrove freely in the piston
grooves.
DK 1436
Fig.2.1Ol3 .-
Seqerence ond
[Jlethod ot Fitlingl
Piston Rings
( Mork Positioning).
Fronr top to bottom: chromium-ploted compres-
sior.r rinq, bevelied compression ring,
spring
locrded exponding oil control ring
Fit the {irst ring in cny orbitrory position
(its cylindricol chromium-ploted peripherol
port
is chomfered on either side,
focilitoting identi-
f icotion), the second, bevelled ring with
the
lettering 'TOP"
or onother mork
on top, ond
llre oil lontrol ring with its
outer shorp
edge g>ointirig
dowtrword. lf
tl-rere is
ony doubt os
to
the coriect selection of
the rings, check them
for proper seoling in
the cyli.nder.before os-
rurbty. ltrsert tlre ring into
the cylinder ond
level it by pLrshing
home the piston heod' In
the cose of
o used cylinder, insert
the ring
obout 20 ntin
below the
top edge of the cylinder
lirrer, i. e.
o plcce rvhere the
cylinder. liner
is
olreodv worn, while checking for
the right
clecronce in the piston
groove ond for the
correct gcrp in the
cYlinder bore.
For ri"ngs
thot hove not
been run-in,
the
fol'
lowirrg circumferentiol gop or
contoct cleoronce
with rlgord to
the cvlinder liner
is permissible:
none foi the chromir-rm-ploted compression
ring,
two in c totol ronge
of on ongle of
35 degr' for
the bevellecl compression ring
ond the oil
control ring. Lcrger
contcct cleoronces olong
the circumTerence denote
either on
incorrect
selection of
the ring, for exomple the
ring
does
not correspond to
the cylinder bore, or
on
excessive weor
of the cylinder liner.
Check the ring gop cleorcnce using
feeler
goLrges- For new
compressiol
lngs, this
gop
.leo"ronc" should
be
0.25 to 0.40 ntm, for
new
oil corrtrol rings
0.20 to 0.35 nrnr. The
nloxinrtlttt
oernrissible cleoronce
of
worn rings is 1mm'
48
105 r20
'.;iA
'!.t l
\Lt { .,
x),:=
s!-9
f:ig.2.1A14 -
Checkinq Pi.;ton Ring
Gop

{
Smoll End ond
Big End Alignment
A misolignment of the centre line
of the
smoll-end bush ond big-end beoring
or the bore
for the big-end
beoring shells must never ex-
ceed 0.03
mm per 'lO0
mm of the connecting
rod length. For checking
ond olignment use
the
MP 1-102 or 1-159 f ixture.
Insert the odiusting pin
into the fixture ond
set both its diol indicotors to
zero. Clomp the
connecting rod without shells
into the fixture,
threod the pilot
pin
in it, ond swing
down the
connecting rod. The recdings
of the diol indi-
cotors will
show ony misolignment of the
smoll
ond big end. The moximum misolignment must
not exceed 0.03
mm os olreody mentioned.
Check for misolignment in two plones by tilting
the diol indicotors.
Two pilot
pins ore supplied, one with o
di-
ometer of 20 rnnr. the
other with o diometer of
20.05 mm, to motch the gudgeon
Pins.
To Motch Connecting Rod
with Gudgeon Pin
ond Cronkshoft
With regord to the reciprocoting movement
of the piston,
the gudgeon pin must hove
the
smollest possible
cleoronce in the
connecting
rod small end (ony lorger cleorcnce results
in
pin knocking). Therefore
select from
severol
gudgeon pins
one which will
be o close running
fit in the smoll-end
bush. lf no suclr pin is
ovoiloble, reom
tlre bush but never exceed the
moximum toleronce limits.
An oversize buslr lros to be
reomed to o nom-
inol diometer of 20.05 mm. For
the respective
dimensions refer to
the Toble supplied with
gudgeon pins. The big"end
beorings
i:;hells)
inouta be
selected occording to the nominol
diometer of the cronkpin. The
shells lrove no
diometer ntorking
oncl hove to be identif !ed
by meosuring their woll thickness with o mi'
crometer.
Motching Big-end Beoring
shells
with Cronkpins
MotchingCronkpin o"|,,n"iifl",,l ro,u,on
nominol diometer
1 thick"ness
mm
mm mm
45 (stondord)
44.75 (1st
regrinding)
44.50 (2nd
regrinding)
44.25 (3rd regrinding)
44 {:lttr regrinding) 1.490
1.615
1.740
1.865
1 990 0.007
Numericol lderrtif icotion of
Connecting Rods
For better identificotion, {igures con
be
stomped on the bosses of
the connecting rod
big end ( see Fig 2 11
1) . The f igures corre-spond with
the
number of the respective
gVtin-
derwithwhich theconnecting rod
is ossembled.
When replocing o connecting rod,
provide the
new connecting rod
with its very some identi-
ficction numbel. Stomp
the figures os much
toword the for end of the boss os possible to
ovoid fouling the loterol guide foce.
2.12 CYLINDERS, CONNECTING RODS
AND PISTONS
o) Only o cylinder (liner)
ond piston of
equot
'
diometer ond the some toleronce closs con
be ossembled qs
s unit.
b) Theengine cs qn
ossembly unit con befitted
cnly with cylinder liners ond pistons
of the
some diometer, the pistons being
of the
some weight grnLtp.
The inclividuol cylinder'cnd-piston qssemblies
con be, however, of dif
ferent toleronce
closses. On the othe'r hond, connecting rods
of only the sqme weight group
con be used-
These ore the cc;tditions for
the correct op-
erotion of pistons in the
cylinders ond for the
correct boloncing of the cronk mechonism.
For detoils concerning dimensions (diometers),
toleronce closses (cylinder liners, pistons) ond
weight groups
(connecting rods ond pistons)'
refei to fhe chcpters deoling with
the
individuol
pc|rts"
To Assembie Cylinder Liner
with Piston
qnd Connectirrg Rod
1. Toke cylinder liners ond pistons with
motching dinrensions, i. e.
cylinder liners of the
some boie (they need
not be necessorily of the
scrme toleronce closs), pistons
of the some
cliometer <,nrl tcieronce closs
to motch those of
the cvlinclr:i iitrers
ond of the sonre weight, oncl
connectitrct rorls, of rtne of
tlle twtl weiglrt
cl roLr PS.
lti''
DK 1161 2.
1
OCCorl Selec'
cyl i nd
tolpro
the (
motch Son
pin or
gudge
in wh
suitob
bush.
Mor
respor
with v
meric<
Rod'.
3.L
the gr-
80"c i Sme
home
some
threod
Pin, o
circlip
on thr
pressi I
Fit
hole ir
the orr
4.F
or exp
detoils
the ri
groove
5- Pr
the crc
ond co
2.13 I
In or
ter ist ic
coms o
comsh<
c leoror
the cor
Volve '
with
lntoker
open be
close o
Fi,c 2.1211 -
Press'f ittirrg
of Gudgeon Pin into
Piston Usinq MP 1-i04
Drift
50

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