YANGDONG Y90 Series Manual

~®
SERIES Y90 DIESEL ENGINE
OPERA TION & MAINTENANCE MANUAL
VANGOONG co., L TO.
THE PEOPLE'S REPUBLIC OF CHINA

FOREWORD
Series Y90 multi-cvlinder ditsel eneines are ideal power units for lieht vehicle,
aeromotor.small tractor,air conditioner in bus,eenerator set and en2ineerine machinery.
The normal and reliable operation and lone service life of the eneine depend n'ot only
on the manufacturine quality,but also on the reasonable operation and correct
maintenance.
In
order to provide the detailed description and instruction of this eneine for
operators to manipulate
it correctly in short time,we offer this manual which briefly
describes the performance
of series Y90 diesel eneines to operators
19
maintenance workers
and relevant maneers.
Since the construction
of this eneine is sub.iect to frequent improvement and
development durin! production and practice
19
it is possible tllat the eneine supplied is
somewhere not exactly the same as one described herein.Please pay attention to that when
readine the manual.

Warning Notice
1.It is strictly forbidden to use inferior and dirty diesel fuel or lube oil. Please choose
to use fuel
and lube oil with stipulated number accordioe to the instruction.
2.It
is strictly forbidden to leak out from an intake system(air filters.pipelines and
connectin2 components).
3.It
is strictly forbidden to have hard water(well water or soprine water)as cooline
water,If necessary to apply the hard(water),soften it first.
4.lt
is strictly forbidden to start under the circumstances of lack of lube oil or water.
5.It is strictly forbidden to operate
at overload or under other conditions aeaiost the
rules.
6.lt is strictly forbidden to reaulate the fuel in.iection pump at will.
7.It is strictly forbidden to chao2e the diameter of the pulley.
S.To control the
startine time(less than 15 seconds) and the startine interval (more
than 2minutes) strictly_
9. It's amust tomaintai. the diesel en2ine techanically in the allotted time.
to.Unskilled workers
are not allowed to dismantle and assemble the en2ine and its
spare parts.

CONTENTS
I .Configuration and Installation Dimensions of Model YSD490Q Diesel Engine I
II .Performance Curves of Model YSD490Q Diesel Engine ..........•..................• II
SECTION 1. DIESEL ENGINE SPECIFICATIONS AND
TECHNICAL DATA
I . Specifications of diesel engines .............................••.. ... .•. ••• •.• •.. I-I
II .Specifications of the main accessories··· .........•.•.....•... 1-2
III .Main technical data of diesel engines . ........•.....•..... 1-3
IV .Fit clearance and wear limit of main parts .. •.•...•..•.•... 1- 4
SECTION 2. OPERATION
I . Fuel oil,lube oil and cooling water ......................••.........•...••......... 2-1
II .Preparation before starting ... .•• ... ... ... •.• .•. ••. . ••...... 2-2
III .Starting .•........•......•.............•.. 2-2
IV .Operating . ........•.•.•.•........••..•. 2-3
V . Stopping . .•.....................••.... 2-3
SECTION 3. MAINTENANCE
1 . Routine maintenance . 3-1
II .Maintenance after every 100 accumulated operating hours 3-J
III .Maintenance after every 500 accum~lated operating hours··· ..• •.. •.• 3-2
IV .Preservation and storage of engine ............•...•................. u ••••••••••••••• 3-3
SECTION 4. ENGINE ADJUSTMENT
I . Adjustment of valve lash . ~ 4-1
II .Adjustlnent of injection timing ···4-1
III .Adjustment of injector .4-2
IV .Adjustment of lube oil pressure . ···4-4
V . Adjustlnent of injection pump .4-4
VI .Adjustlnent of decompression ann lash :·4-4
SECTION 5. CONSTRUCTION OF DIESEL ENGINE
I . Cylinder head 5-1
II .Cylinder block 5-2
III .Piston and connecting rod 5-3
1\1 .Crankshaft and flywheel .5-5

v . Camshaft "5-5
VI .Gear transmission system 5-6
\'lI .Fuel and governing system "5-7
VIU •[ .. ubricating system 5-8
IX .Cooling system ······5-10
X. Electric system 5-11
SECTION 6. FAULTS AND REMEDIES FOR DIESEL ENGINE'
I .. Hard or refuse to start .........•.. 6-1
II .. Power jnsufficiency ......................•••.• .6-1
III .Stnoking exhaust 6 2
IV .Knocking noise in engine 6-2
V . Lube oil insufficiency or no pressure··· •..... .•. •........... 6-2
VI . Overheatin~ of engine 6-3
VII .Engine running-a\vay 6-3

Exhaust outlet centerline
1:2 ~60 ~46
215,',
View~
530
214.7 i 201
=~----,fl4 I 134
17Y ----r-n9
Vie", B
~116H1r:'O~l
135
j)4.5
I ~b
lxhdUSf viJaet Ceftl~me
Connecting dimp!1sions of flywhe~l and its hDirdng
~-J.Jf
~
CD
f"t"I'---
-0.
~
r-
'-OIIJ'"\
('-.J
~
I. Configuration and Installation Dimensions of Model YSD490Q(YS490) Diesel Engine

ge
(glkw·h)
250
1
230
.... -.....-..... -- .....- .... ---.-- .....-.....-..... Me
(N·m)
160
ISO
35
25
1600' 180Q. 2000 2200 2400 2600 2800 3000 3200
n. Performance Curves·of Model YSD490Q Diesel Engine
n

SECTION 1. DIESEL ENGINE SPECTFICATIONS AND
TECIINICAL DATA
I.Specifications of Diesel Engines (see Table 1)
Table t
Model YSD490Q
Number of c;"finder
. Bore(mm)
4
90
Stroke(.mm)
CompreSSion tatio
I
!
I
100
18
_._----------_ .... --_._-------------_ .. __ ._--------~--.------'\_.. -------_ .. _--_ ........ _------ ..... _----_._ ... _--------- . __ ._--------_._-----_ .. _ .. _._--- ..... -
---- ... _~-~-_ .. __ .. _-------~-~-------------~-~-----~ .. _------------~----------------~-------------~-
Total displacement(L)
Fuing order
2.54
1-3-4-2
37.0·~45.6
Rated PO\\ er(k W)
~-----_- ----------_-_--_-_-·----_--_---ti----.--- ~ ~ _
Rated speed(r/min) I 2600--3200
- -- ._--_ .. _-_._ ... - .. _-------_._----_._-_ .. ~_._---------_ .. _.-...!-. - ------- ._-- -_._---- .... _--- ---. __ ._------_ .. _---- ---._--_ ... __ ._------_._._--._ .. _.- _ .... _._.
Max Torque(N m) ~ 149.3
----_ ... _--_ .. _-------------------_.-._-_._-_ .._----_.-_. __ .-_._._--~_ ... _--------_. __ .. -----,-----_ .... _._---,---_._._--
Min Specific fuel consumption at full load
(glkW.h)
--.--------- .. - --.---- ..... -.------------------.---+- .. ---~------ .. ---------- .... ------------ .... ----.-.---.--.----.---.----- .... -- .. -.---- .. ----1
Oil- fuel consumption ratioC~)
Advance I t~ection Angle/Speed
(Before TOC) (OC)(rpm)
Specific lube oil ccnsumption(g/kw.h)
Direction of crankshaft rotation
(facing to flywheel)
!
I
~O.8
15± 1/2800
With Advance Device
i
2.72
Counterc loc·k wise
18±
1/2600
Cooling Inethod
Lll bricating method
Startting method
Forced water cooling
Pressure and splash lubrication
Electric
.---------- ---------.-.---.---------. ---·----·----------1-·----- ..... --·-----------·-------- .. -------------------------·-------------- .. ---------------1
Net lnass(kg)
OveraU dimensions
(LX WX H)(mm)
1-1
230
716X530X670

n .S~·ification of Main Accessories(see Table 2)
Table 2
Designation
6
Nil
F
I Specification
YSD490Q
--------,
l-- Type .. . Series I or BQ pump
Fuel injection r== ~ovemor _ all-speed, mechanical centrifugal ------
pump I Plunger diameter(mm) 8
~+ . --i_--~el d~~ pu~ =t Single-acti;:-:----is--to-n----type----------
2I
Fl" t ~ ~~~!e set I ZCK154-S427?r CN-DLL~~~~~~~ _
I ue InJec or i •
I ~.E~~t:~~!~~eh~le(~Ei) _4 holes, <IlO.27
i! Injection pressure(Mpa) 19.6+
01
--------1--------------------,----- ----------------------------------------------------
I ~.-.----.-------!~~-------I--------------Rotor type . . _
3I Lube pump 1-----c:=~~1a~L)----1--------·----·-·-- ~~~: .--~--------------
I! --------- ---------.- .---.-.----------- ----i--------·-------·----------·-------·----------------
i . i Pressure(kpa)! 400
-.----.--t---.--------.---.-----:---.-----------------------·--------------r-----------------------------·--------------. -- .. ----
Ii Type i Centrifugal.. volute, single-suction
1.....-._-- . . . ... .. - __ . .-+ . . . --- __ . . .. .. __
!.. Speed(r/min) I .. 4000
4i Water pump ~-~-~~~-~~:~i~~~2 --4----- - =~-)~~---=~===~==-~=
-- .-t-.-.- --- ... -.-.-.--- -j--. -.-. ---- .- ... - -·-·-·······-------t-.----- -- .. -----.-- .-------------.-----------
; I Type! Series DC motor
I 1- -- ------- --- ------ -------,---------------.---------------------------
I. 'l Model i QD1315A,D138Y
5i Startmg motor 1~-·----Vol~ge(V)------I~---- . 12 .
I r---------------------------I-------·-·----·-----------·-.--------
I ~ Power(kw) I 2.5
-------t---------·- - --_.--_.-, ------------Typ;---------··-l----------sil-i~~n re~tifY~g-~hunt dymam~--
f-· .. - .. -----------·-·-------- .. ·--·-- .. ------·---~-------··------------------- .. -----------------------.-----------------
i Model I JFIIA
Dymamo r---------------------------------- --.---.----t------------------------_ .. ---- -------.--.-- ... - -------------.-------------- .. --
! Power(W) i 350
f------ ... ----- --.--_ .. -----. --- --.-.-----j--.-------- .. --------- ...... - .... - ------ ---.--------.------------------.--.- .--
I Voltage(V) 1 14
-------1--· ... - -.-------------f-- .. ----------.------- ... ----------------.---r---------.--------.-------------.-------------------
7! Fuel filter I-.------J~:I.-.--------f-~-.---------~!~gle sta~~:~~eleme~------_--
.---, -- -----,-----------------------1--------------·----·------------------------.-.- .. ---
I . I Type ! Single stage,paper element
8I Lube 011 filter f------------------------------ ... ----- .. ------------r--·---·----.---.-------.----------- .. --------- .. -------------.---- ... ---.---
Ii Model I J0801H
------1"- - .. ---------.--- ... --.-- .. +-------------.--------.-------- .. ---- .. ---------------·1--··---·-------- .. ---------------·----------
i. !. Type! Oil-immersed
9 \ Air titer . -------- .. ------ -------- .. -- ------- - _ - --------j ------------ .. - .. -.-- .. ------.--- .. - -- - .. ---.--- .. ---._-------.-----.---------- .----
: : Model! CN212
- .. -- .... --.)" --. - .. - -----· .. ·----- .. --_ .. ---·--1------------·-·- ... -------- .... -- .. -.-----. -----_ .. --------. t---·----- .. --- .. --·---------------·--··----- --------------------- .. ----------.- .. _---
! Electrothermic ! Type i Shrorded
10 : f--- -.---- .. -.---.-- .. -- --.-_.-.----- .....-------!--- ---.- .. ---.---------------- .. ---_.,,-. --.--.------. -----------.--------------- ... --.------------- ----
! plug I Model! Nil accessory
1-2

~ 900rpm
5% -- 10%
ill.Main te4:hn.ieal Data of Diesel Enline
1. Valve lash(mm)
Intake valve(cold)
0.30- 0.35
Exhaust valve(cold)
0.35- 0.40
2. sinkage
ofvalve(mm) 0.7- 0.9
3.Torque limits
of main bolts and nuts(N· m)
Cylinder head bolts 125- 145
Main bearing cap bolts 140- 160
Connecting rod bolts 100-.." 120
Flywheel bolts 100- .... 120
4.Temperature
and pressure limits
(l)Exhaust temperature(OC )
n~ 3200rpm t~ 620
3200rpm>n>2600rpm t~ 600
n~ 2600rpm, t~ 550
(2)Lube oil temperature(OC )
~ 100
(3)Lube oil pressure in Main Passage(Mpa)
At normal operation 0.2- 0.45
.l\t luin. Steady Speed ?0.05
5.Govemor Characteristics
Min. idling steady Speed
Steady regulation
]-3

IV' .• ~it Clearance and Wear {.limit of Main Parts(see Table 3)
Table 3
Designation
I
I
Assenbly limit' Wear linlit
(mm) (mm)
Connecting rod journal and connecting rod bushing
2Piston pin and connecting rod small end bushing
3Piston
skirt and cylinder liner
0.060-0.172
0.025-0.050
0.130-0. 195
0.25
0.10
0.40
... _._-_ .. -.• _._ .. -_ .•---.._.. _ '-"'-_- .. _ ~ - .• _. __ •. _-_ --- •.... - -- . __ •... _ ·1 _. __ "''' __ ···_···· __ ·• ~·.· .. ·-.·--------.---······-·I
4Side clearance bet\veen the .~ st ring and its groove
O.070-0~ 102
0.20
5Side clearance bet~reen the 2nd ring its groove 0.050-0.082 0.15
6Side clearance bet\veen the oil scraper
r~ng and its groove 0.030-0.062 0.15
7Gap
of the 1 st ring
0.300-0.450
_._.'--' -' .. - "-'--" .._ -_ _ _._._- --.- ., _ .. +--.- .. __ .. ---.---- --- ..- .. -t - - .-
8 Gap of the 2nd ring and oii scraper ring
9 Crankshaft main journal and main bearing
0.300-0.450
0.070-0.149
0.25
••. ' •• _ •• • c __ ..
rCalTIstlan .... journal and bushing
]1
Idle gear shaftjournal ~nd bushing
0.025-0. 114
0.025--0.075
0.18
0.18
.... -- - -_ __ - """'" -- - .. - "'-'-'-'-_._._ -- ~., ..- .. __ ---- - .. -.- - -_.- ..- __ -.--+-- - .. - - ,,---- -----+-.- -- .. - -- - - '-1
12 Intake valve stem and valve guide
13 Exhaust valve stem and valve guide
14 Rocker arm shaft and bushing
15 Axial ClearcltlCe of crankshaft
0.025-0.077
0.040-0.092
0.016-0.061
0.075-0.265
0.15
0.15
0.20
.. -_ .. _- .. _ -._" -_._-- _ .. __ .. --.- ..•... - _. __ ._ - ..., _-- _. __ ._--- __ .;- _- --""'.'--"-"-' ._ ..
16 l\xial clearance of canlshaft
1-4
0.080-0.250

SECTION2. OPERATION
I . Fuel Oil ,Lube Oil and Cooline Water
I.Fueloil
Users can select the proper ~ade of fuel oil accrdin~ to the local ambient temperature.'.Jn
the
~eneral area in China,the ~de of fuel oil is accordin~ to the standard GB252 li~ht dies~1
fuel.Use ~rade "0" light diesel fuel in summer, while in winter, use grade "- 10" light diesel
fuel.Before
bein~ filled into the engine fuel tank,the diesel fuel must be settled for along period
(normally at least 48 h).Then
draw out the upper part.The fuel should be filterd by silk cloth
while filling it into the engine fuel tank.It will extend service life
of injectors and injection
pumps
by usin~ the well settle diesel fuel.
2.Lube oil
In the ~eneral area in China,users can select the proper' grade according to GB/Tl1122
Lube Oil of Diesel Engine.Use grade CD40 lube oil in summer,while in winter use grade CD30
lube oil.When
bein~ filled into the engine oil tank,the oil should be filtered by screen.
3.Cooling water
It is recommended to use soft water
such as rain water,city tap water,or clean river water for
en~ine cooling.Well water or tap water f~om well water could not be used. Cooling water
containing too much minerals will form water scali in an engine cooling system,affecting the
engine cooling efficiency and giving rise to engine troubles.
Hard water(well
or spring water,etc.) should be softened before being used.There are two
softening methods;
(I)Boiling up the hard water;
(2)Adding
20g caustic soda (sodium hydroxide) to each 30L hard water to make up a
solution.
When the engine operates in cold weather where the cooling water is liable
to freeze,anti -
freezer can be added to the cooling water to prevent it from
freezin~. Glycol or alcohol aqueous
solution
is most ordinary.
If it is difficult to start the engine under IOYler ambient temperature, heat the water to about
80°C before filling it into the cooling system.
2-1

II .Preparation before Startine
I.Check the ti~htness and reliability of ali connectin~ parts. Check control levers (speed
control
lever and stoppin~ lever) to see whether they can be moved freely.
2.Rotate the crankshaft several turns"be sure that all movin~ parts move freely.
3.Check the oil level in the oil sump and injection pump to see whether it is kept within two
marks on the dipsticks.Make sure that the fuel tank has sufficient fuel and that the fuel pipel~nes
are unblocked.
4.0pen the fuel tank cock .. Check whether there is a.ir in the fuel system. If necessary,Joosen
the vent screws on the fuel filter and injection pump,operate the primin~ pump on the fuel
delivery pump by hand until the fuel flows out of these screws without bubbles,and reti~hten the
vent screws.After that,loosen the union nuts of injection pipes on the injectors an~ rotate the
cankshaft to bleed air from in1ection pipes,then retighten the union nuts. Check all fittings of the
fuel system to see whether there is any leakage at all joints.
5.Check the radiator
to see whether it is filled fully with water and whether there is any
leakage at all ioints.
6.Check the accessories to see whether they are firmly and reliably connected.Check the
electrical system to see whether the battery is fully charged,all wirings are correct and all
connections are tightened.
7.Check the clutch to see whether it has disengaged.
m. Startin2
1.Set the speed control lever at the middle speed position.
2.Tum the ignition switch to "preheating" position to heat the electrothennic plug for 20r~.
30s.
3.Turn the ignition switch to "on" position.Press the starting button to start the engine.lf it
fails to start.,release the button immediately.Wait 2minutes 3Ininutes .. before starting the engine
again.lfthe engine fails to start after 3attetnpts.,check the cause and remedy the fault.
4.As soon as the engine has been started.xelease the press button itnmediately.Then tum the
ignition switch to another position to charge the bat1ery. At the same titne move the fuel control
lever until the engine runs at idling speed.C~heck the operation condition of the engine to see
whether there is any abnormal noise.EspeciaJly pay close attention to the readings of oil pressure
gauge,which should be within specified pressure limits."Then \varm the engine up with engine
speed gradually increasing to 1800-~-J 2000r/min
2-2.

IV .Operatin2
1.00 not load the engine until the cooling water telnperature is over 50°C and the lube oil
temperature is
over 40 "C . The engine should not be operated undrer rated operated under rated
output before the outlet water temperature reaches approximately 80°C .
2.1ncrease
or decrase the engine load and speed gradually and evenly.In normal case,do not
load
and unload the engine suddenly.
3.During operation,observe the gauges on the instrument panel frequently where the
readings should be within the specified limits.Pay close attention to the exhaust gas color and the
operatingnoise.lfthere is any fault..stop the engine and inspect it.
v.Stoppine
1.Before stopping..take off the load and reduce the engine speed gradualJy.Let it run at
idling speed for afe\\' minutes.Do not stop engine until the outlet water temperature fans to
below 70°C.
2.Afier
stopping the engine, the ignition s\vitch should be turned to the middle position.
3.1n winter,when ambient telnperature falls to bellow 5 °C ,after the engine stops and the
cooling \vater temperature falls to below 60 "C~ .,open all drain cocks on the cylinder block and
radiator to drain
off all \vater remnant within the cooling systelTI.,in order to avoid dalnages 01
parts due to freezing.If anti ---. __ .freezer is added to the cooling water,it is not necessary to drain
off.
2-3

SECTION3. MAINTENANCE
For reliable engine operation with less wear and longer service life,all maintenance work
must
be carried out as follows.
I . Routine Maintenance
I.Check the oil level in the oil SUlnp and it should be between two marks on the dipstick
and near the upper one.For a new engine or the engine reused after stopping for along period,the
lube oil must
be filled to the upper mark,and operate the engine at lower speed for 5 ----- 10min,
then stop
the engine and measure the lube oil level once again.
2.C:heck the cooling water level in the radiator.
3.Check the lube oil level in the governor of the injection pump,replenish the oil to the
specified level if needed.
4.Eliminate oil"water and gas leakags of the engine.
5.Check tightness and correctness of all components attached to the engine.
6.Check tightness
and reliability of engine foundation bolts and the conn~ction between the
engine and the dirven Inachinery.
7.Keep the engine clean.Oil,water and dust gathered on the engine surface should be wiped
away \vith adry rag or cloth dipped in gasoline.Especially keep the electric equiplnent clean and
dry and clean out the dust on the fins of the radiator.
S.For
the new engine"after SOh t(ial running,renew the lube oil in the oil sump,fuel injection
pump and governor,and tlush the oil filter elclnent,oil sump and oil strainer.
9.Promptly elinlinate the troubles and faults found.
II .Maintenance after Every 100 Accumulated Operatine Hours
Besides the ,. routine Inaintenance" \vork,and the follo\ving items:
1. Rene\v the oiIin the sump.
2.Clean the oil filter
or renew the paper element if necessary.
3.(~lean th~ fuel filter or renew the paper element if necessary.(1t may as \vell be replaced
after every 200 acculTIulated operating hours.)
4.Clcan the oil filter or renew the paper eletTIent if necessary.
5.(~lean the valve lashes .. readjust theln according to the recotTIlnended procedure if
necessary.
3-1

6.Check the tension of the fan belt,and readjust it if necessary.
7.Fill the nipple of cooling water pump bearing with ZG- 4 calciumbased grease with a
grease gun.
8.Clean out the dust in ,intake manifold'lclean the inside of the aircleaner,brush otT the dust
gathered on the paper element surface,and clean the inside of the exhaust manifold and silencer.
9.After every 200 accumulated operating hours,check the injection pressure and spray
pattern of iniection.lf necessary .. dismantle the injector,clean the nozzle set,and readiust the
injection pressure.
IO.Check the voltage of battery and the specific gravity of battery acid .. which should be
within 1.27r'_ 1.28( at ambient temperature of 20°C ). When it is less than 1. 14,the battery should
be recharged.The level of battery acid should be I0 .'~--, 15mm above the pole plate.lf insufficient
add distilled water to the required level.
11.AII parts dismantled for maintenance should be washed,and cleaned and correctly
reasselnbled.l\fter reasselnbly.stat1 the ~nginc and check \vhether it is in proper operation,AII
faults
should be retnedied.
ill .Maintenance after Everv 500 Accumulated Operatine
Besides the work of Inaintenance after every 100 acculnulated operating hours .. the
following items are needed:
I.Check the injection pressure and spray pattern of the injector.lf necessary .. dislnantle the
injector'lclean the nozzle set and readjust the injection pressure.
2.Check fuel delivery of the injection pump,and recalibrate it on a test bench if possible.
Check the injection tilning,and readjust it if necessary_
3.(~heck the sealing of the intake and ~xhaust valvcs.lf necesary .. grind and lap the valve
seats and readjust the valve lashes.
4.Check the tightness of the connecting '.>a roo.,mian bearing cap and flywheel bolts.
5.Retightcn the cvlinder head bolts and adjust the valve lashes according to directions given
in
section 4.
6.C:Iean or replace the paper elclnent of air cleaner.
7.('lcan the cooling ~ystem.T'he cleaning solution can be prepared hy adding 150 granls ot
caustic soda(Na()H) to every litre of v~ater.Before cleaning_drain the systelll cOlnpletely and then
fi II in the saIne capacity with cleanIng solution.Let it relnain in the systenl f<lr 8 r- -~ 12h. Then start
the en.glne and run it until the tenlperature of cleaning solution reaches normal operating
tClnperature.Stop the engine and drain the system itnnlediately in order 10 avoid settling of scale
\vithin the systetn.Final1y,tlush the system with clean w'ater until all seditnent is flushed out.
3-2

8.Check whether the thermostat is in good order.Examine the water dropping out from a
weep hole
of the water pump.It is necessary to renew the water seal,if flowing out too much of
water.
9.Check the wiring contacts
of the electric equipment to see whether they are connected
firmly and well.Bumt marks should be removed.
1O.After
every] ,000 accumulated operating hours,add the following items;
(1 )Make an overall check on all parts and components.Make necessary adjustments and
repairs.
(2)Dismantle the dynamo and starting motor.Clean out
the dirty grease in the bearings and
refull thern with clean grease.Check the pinion
of starting motor.
II.After every 1,500 accunulated operating hours,add the following items:
(t )Rernove the cylinder head,check the valve and valve seats and other parts of cylinder
head asselnbly.
(2)Remove the carbon
d~posits on the surfaces of cylinder head,liner, piston and piston ring,
etc,and wash down them.
(3)Check and measure wear
of the pistons and piston rings.
(4
)<.-:heck and rneasure wear of the cylinder liner.
(5)Check and measure \vear
of the crankshaft main journals and crank pins.Clean lube oil
passages
of the crankshaft.
(6)Check \vear of the Inain bearing and connecting- rod bearing shells.
(7)Clean oil passages
of the cylinder block and replace lube oil.
IV .Preservation and Stora2e of En2ine
If the engine is to be put out of service for acOlnparatively long period of time,it is
necessary to preserve it according to the follo\ving procedure:
I.After the engine stops and still does not cool
yetdrain out conlpletely the lube oil,cold
water and fuel itnrnediately.Clean the oil sump and oil strainer.
2.Clear out the dust and oil on the engine surface.With antirust oil sinear all the unpainted
exposed surfaces
of engine except rubber and plastic parts.
3.Heat the filtered lube oil 10 )
10 120 'C'; .. until all bubbles in the surface of oil disappear.
~rhen pour the dehydrated oil Into the oil sunp until oil level reaches the upper mark.,and turn the
engine,in order to nlake sure that the lube systenl
is cOlnpletely tilled up with this oil.
.1-3

4.Pour some dehydrated oil into cylinder through injector -assembled holes on the
cylinder head,and turn the crankshaft to make sure that the piston,piston ring,cylinder liner and
valve seat are
alJ covered with alayer of this oil.
5.Block the outlets
of intake and exhaust manifolds (silencer)with wooden plugs or wrap up
properly with plastic film in order to prevent any dust from getting in.
6.The engine should be stored in aclean room with good ventilation and low humidity.,The
engine should be covered.Chemicals near it are strictly prohibited.
The preservation according to the above procedure may be valid for 3months.Over this
period,repeat the procedure.
3-4

SECTION.4 ENGINE ADJUSTMENT
Fig. tAdjustment of valve lashes
3. slip afeeler gauge between th,-:~ rocker arnl
and the tip of the intake or exhaust valve steins of
the 1st cylinder respectively to check and adjust the
valve la~;,hcs.lntake va.ive lash and exhaust valve
cover ofthning gear housing.
2.Turn the crankshaft to rnake sure that the
piston
of 1st cylinder is at the conlpression TDC
position.'The tirrling nlark on the inspection window
of the fly\vheei housing exactly points to the '. 0"
tnark on the tly\vhecl ritn '!or th{~ " 011 rnark on th{~
crankshaft pulley is aligned \,,"ith the pointer on the
I .. -\d.iustJnent of Valve I.J3sh
When the engine is maintained and repaired.,it is necessary to check and adjust the valve
lashes.'fhe recommended nlethod of adjusting the
valve systenl and valve lash is as follows:
stands.
1.Remove the cylinder head cover.(~heck and
tighten the nuts fastening the rocker aml shaft
tash in cold l11ust be tht: value specified in section) .1l·len after turnin~~ the crankshaft by 180"
to adjust the valve lash of other cylinders according to the engine firing order(! -3- 4-2)for the
four cylinder engine and' -3-2 tor three cylinder engine.
II. Adjustment of In it~tion Tiolinf,!
1\1 obtain the tnosl econon1ical specific 111ei conSllInption and to ensure norlnal operation of
th~ engineJnjection tirning should be adJusted properly.For the Model 485 die~el engincs,the
ang)c at \vhich injection begins should be the value specified in section I .
'fhe adjusting inl~thod of injection timing is as l(lllo\\'s:
1. Vent the air trapped in the fuel system'land t, ~ln the crankshaf-t to f111 up the injection
pUlnp \Vl!h fuel.l)isconnect Hle injection pipe of the 1st cyiinder..turn the crankshaft slowly in the
direction of its rota[;on and at the satne tin1C ohserve the fuel level in the hele of fuel pipe union.
\Vhen this
fuel level iust starts to risc'!stop lurn the crankshaft imtnediately.
4-1

2.Check the timing mark on the inspection window of flywheel housing to see whether it
aligns with the correct gradulated mark of specified advanced injection angle on the flywheel rim
(or on the crankshaft pulley).
3.ln case that they do not match \vith each other,the advanced injection angle can be
adjusted by removing, off the front cover on the tinling gear housing and loosening the three
screws fastening the injection plunp tilning gear support(see tig.2).lf the injection timing is too
advanced,turn the timing
gear support anticlockvvise to the proper angle.Otherwise.turn the
support clockwise.If adjusting range is not enough
Fig. 2Adjustment of specinect
advanced injection angle
loosening the three nuts on the
adjusted hy
due to limitation of the three elongated holesJoosen a
little the three fastening nuts on the triangular flange
of the injection pump and tum the injection pump.
Facing
the front end of engines, when the injection
pump rotates clockwisc,the fuel injection will retard;
\\lhile the pump rotates anticlockwise.Jhc fuel
injection will advance.
4.Additionally,if the engine has injection angle
advance device,the advanced injection angle can be
triangular flange of injection pump and turn the
injection pu,np shafLFacing the front end of engines<t
\vhen the injection pump rotates clock\vise,the fuel
injection will' retard:while
the pump rotates
anticlockwiseJhe fuel injection will advance.After
turn the injection pump once.it is lnust to tighten the three nuts and c.heck the advance injection
angle again untill
the advance injection angle fits the spcified value.
ill. Ad.iustment of Iniector
Injector test and adjustment ,nust he performed on ainjector tester in order to adjust
iniectin~ pressure"inspect sprary pattern and relnedy faults.
Too high or too lower Injector injecting pressure,and abnormal spray on dalnaged injector
parts'\vill cause engine troubles'lsuch as black smoking,power and speed dropping .. increasing
exhaust temperature and diesel knocking.,etc.Generally..the "shut off" method is recommended to
4-2