Longjia LJ1P37QMB(3B3) User manual

LJ1P37QMB(3B3)
4-STROKE50cc
SERVICE MANUAL
LCJNG..JIA

CONTENTS
CONTENTS
SPECIFICATION/TIGHTENTORQUE VALVE1
MAINTENANCEINFORMATION 2
LUBRICATIONSYSTEM 3
ELECTRONICALLYCONTROLLED CARBURETORSYSTEM 4
REMOVALENGINE5
CYLINDERHEAD&VALVE6
CYLINDER&PISTON 7
V BELTDRIVINGSYSTEM /KICKSTARTSYSTEM 8
FINALDRIVINGSYSTEM9
ACG10
CRNKCASE&CRANKSHAFT11
STARTINGCLUTCH12

1.SPECIFICATION /TIGHTEN TORQUE VALUES
1-1
SPECIFICATIONS
MAKER LONGJIA MODEL 3B3
ENGINE
Type 4-STROKE ENGINE Ignition Transistorized coil
ignition
Installation and
arrangement Vertical, belowcenter, incline 80 StartingSystem Electrical&Kickstarter
FuelUsed Unleaded (92/95)
Deceleration
equipment
PrimaryReduction Belt
Cycle/Cooling 4-stroke/forced air
cooled Secondary Reduction GEAR
Cylinder
Bore 37.0mm Clutch Autocentrifugalclutch
Stroke 46.0mm Transmission C.V.T
Number/Arrang
ement SingleCylinder Max. HP 25km/h 2.3kw/6500rpm
Displacement 49.46 cc 45km/h 3.0kw/8000rpm
Compression Ratio 12 0.2: 1 Max.
Torque
25km/h 3.5N.m /6000 rpm
Idlespeed 1900 100 rpm 45km/h 3.6N.m /7500 rpm
SparkPlug CR6HSA
StandardTorqueValues forReference
TYPE TIGHTEN TORQUE TYPE TIGHTEN TORQUE
5mm bolt nut 4.5~6.0N.m 3mm screw 0.5~0.8N.m
6mm bolt nut 8~12N.m 4mm screw 1.0~1.5N.m
8mm bolt nut 18~25N.m 5mm screw 3.5~5.N.m
10mm bolt nut 30~40N.m 6mm screw SH nut 7~11N.m
12mm bolt nut 50~60N.m 6mm bolt nut 10~14N.m
8mm bolt nut 24~30N.m
10mm bolt nut 35~45N.m
SPECIFICATIONS.............................1-1 TORQUE VALUES (ENGINE).............. 1-2
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1. SPECIFICATION / TIGHTEN TORQUE VALUES
1-2
TORQUEVALUES (ENGINE)
ITEM Q'TY
THREADDIA
(mm) TORQUE VALUE(N.m)
REMARKS
Cylinder head bolts 2 6 8~12
Cylinder head left side cover bolts 2 6 8~12
Cylinder head nuts 4 6 12~16 Applyoil tothread
Cylinder/cylinder head two-ends bolts 4 6 7~11 Tighten tocrankcase
Tappet adjust holecap 2 30 13~17
Camshaft sprocket bolt 1 8 20~25
Right crankcase cover bolts 10 6 8~12
Pulse generator bolts 2 5 5~7
Valveadjustment fixingnuts 2 5 7~11 Applyoil tothread
Sparkplug 1 10 10~14
Engine oil filter screen cap 1 30 13~17
Engine oil drainplugbolt 1 12 20~26
Gear oil drainingplug 1 8 10~15
Gear oil fillingbolt 1 8 10~15
Oil pumpflat screw 2 6 8~12
Left crankcase cover bolts 10 6 8~12
Camshaft chaintensioner pivot 1 6 8~12 Hexsocket bolt
Camshaft chainadjuster bolts 2 6 10~14
Coolingfan bolts 4 6 8~12
Coolingfan cover bolt 2 6 7~11
RR. brakeshoe anchor fixingnut 1 8 15~20
Shroud A/B 2 6 8~12
Start clutch locknut 1 20 70~80
Flywheelnut 1 10 35~45
Transmission(Gear box) bolts 7 8 20~25
Movabledriveface nut 1 12 55~65
Drivepulleynut 1 10 35~45
A.C. generator flangebolt 2 6 8~12
Start motor bolts 2 6 8~12
Crankcase bolts 1 6 8~12
Air/Cconnect bracket bolts 2 6 8~12
Kickstarter arm bolt 1 6 8~12
Inlet pipe bolt 2 6 8~12
Exhaust pipe bolts 2 6 7~11 Applyoil tothread
Thetorquevalues listedinabovetableareformoreimportant tightentorquevalues. Please
see standardvalues fornot listedinthetable.
L0..,.0 .. HA

2. MAINTENANCEINFORMATION
2-1
PRECAUTIONS INOPERATION...... 2-1
PERIODICAL MAINTENANCE
SCHEDULE ....................................... 2-2
LUBRICATIONSYSTEM................... 2-3
AIRCLEANER................................... 2-4
VALVE CLEARANCE INSPECTION&
ADJUSTMENT................................... 2-5
CARBURETORIDLING SPEED
ADJUSTMENT..................................2-5
IGNITIONSYSTEM/SPARK PLUG..2-6
CYLINDERCOMPRESSION
PRESSURE........................................2-7
DRIVING SYSTEM.............................2-7
CRANKCASE BLOW-BYSYSTEM....2-8
PRECAUTIONSINOPERATION
Specification
FuelTankCapacity 6.2L
Engine Oil capacity 800 c.c.
change 700 c.c.
Transmission Gearoil capacity 140 c.c.
change 120 c.c.
Clearanceofthrottlevalve 2~6mm
Sparkplug CR6HSA Gap: 0.6~0.7mm
Idlingspeed 1900 100 rpm
Cylindercompression pressure 9.5 0.5bar/550rpm
Valveclearance: IN/EX 0.05 0.02 mm/0.10 0.02 mm
45Km/h "F"Markinidlingspeed BeforeTDC 13 /2000 rpm
Full timingadvanced BeforeTDC 28 /8000 rpm
25Km/h "F"Markinidlingspeed BeforeTDC 15 /2000 rpm
Full timingadvanced BeforeTDC 28 /6500 rpm
~e
LCNl:ii_JIA

2. MAINTENANCEINFORMATION
2-2
PERIODICALMAINTENANCESCHEDULE
Mainte
nance
Code
Item Initial 300KM
1 Month
Every1000KM
3 month
Every3000KM
6 month
Every6000KM
1 year
Every12000K
M
1 Air cleaner I C C R
2 Fuel filter I I R
3 Oil filter C C C
4 Engine oil change R Replacement for every1000km
5Tire pressure I I
6Batteryinspection II
7Brake &free playcheck II
8Steering handle check II
9Cushion operation check II
10 Everyscrewtightening check II
11 Gear oil check for leaking II
12 Sparkplug check or change I I R
13 Gear oil change R Replacement for every5000km
14 Frame lubrication L
15 Exhaust pipe II
16 Ignition timing I I
17 Emission check in Idling A I
18 Throttle operation I I
19 Engine bolt tightening I I
20 CVTdriving device (belt﹞I R
21 CVTdriving device (roller) C
22 Lights/electrical equipment/mutli-meters
I I
23 Main/side stands&springs I I
24 Fuelpipes I I
25 Camchain I I
26 Valve clearance I A
27 Crankcase blow-byover-flowpipe I Replacement for every1000km
Code:I ~Inspection, cleaning, and adjustmentR~ReplacementC~Cleaning (replacedifnecessary)L~Lubrication
Haveyour motorcyclechecked, adjusted, and recorded maintenancedataperiodicallybyyour LLL Authorized Dealer to
maintain the motorcycleat the optimumcondition
The abovemaintenanceschedule is established bytaking the monthly1000 kilometersasareferencewhichever comes
first.
Remarks:
1. These marks ”in the schedule are emission control items. According to EEC regulations, these items
must be performnormallyperiodical maintenance following the use rmanual instructions. Theyare
prohibited to be adjusted orrepaired byunauthorized people. Otherwise, LONGJIAis no responsible for
the charge.
2. Clean or replacethe air cleaner element moreoften when the motorcycleis operated on dustyroadsor in the
Heavily- polluted environment.
3. Maintenanceshould be performed moreoften if the motorcycleis frequentlyoperated in high speed and after
the motorcyclehasaccumulated ahigher mileage.
4. Preventivemaintenance
a. Ignition system- Performmaintenance and check when continuousabnormal ignition, misfire, after-burn,
overheating occur.
b. Carbon deposit removal - Remove carbon depositsin cylinder head, piston heads, exhaust systemwhen power is
obvious lower than ever.
c. Replace worn out pistons, cylinder head.
LCNl:.-IIA

2. MAINTENANCEINFORMATION
2-3
LUBRICATIONSYSTEM
EngineOil Capacity
Caution
Removedipstick tocheck the oil level. Ifoil
levelisbelowthe lowerlimit mark, add oil to
the specified upperlimit mark.
Oil change
Shut off the engine and removedipstick.
Removethe oil drainplugon the bottom-left
ofcrankcasetodrainoil.
Afterdrainingout oil, clean oil plugand its
gasket and reinstall. Replacethe gasket ifit
isdamaged.
Torquevalue:20~26 N.m
Caution
Add oil tothe specified capacity.
Oil Viscosity: SAE 15W-40, recommended
usingAPI GL-4
Engineoil capacity:
Disassembly:800cc
Change:700cc
When checkingforoil leak, run the engine at
idlespeed forafewminutes, then check oil
capacitywithdipstick.
Cleaning theoil strainer
Drainoil fromengine, removethe strainer
cover, springand strainer.
Ifthereisan accumulation on the screen,
washit off withsuitablesolvent
(recommended usingcompressed air).
Check O-ringfordamage, replaceif
necessary.
Reinstall strainer, spring, O-ringand strainer
cover.
Torquevalue:13~17 N.m
Ÿ
The vehiclemust be parked on alevel
ground when checkingoil capacity.
ŸRun the engine for2-3minutesthen
stop, wait about 2-3moreminutes
allowingengine oil tosettlebefore
checkingthe oil level.
Warmup the engine. Thiswill makethe oil
flowout easily.
oil strainer
strainercover
spring
Dipstick
Oil drain plug

2. MAINTENANCEINFORMATION
2-4
GearOil
Inspection
Check gearoil ifleaking.
Parkthe motorcyclewithmainstand on flat
levelplace.
Turnoff engine and removethe gearoil
drainingplug.
Placeameasurement cup underthe
draininghole.
Removethe oil drainplugand draingearoil
intoameasurement cup.
Check gearoil ifenough.
Replacement
At first, removethe gearoil refillingbolt, and
then removethe drainingplug.
Install the drainingplugafterdrained oil out.
Torquevalue:10~15 N.m
Caution
Fill out gearoil tospecified quantityfromthe
engine oil fillinghole.
Install the oil fillingbolt.
Torquevalue:10~15 N.m
Transmission oil capacity:140 c.c.(120
c.c. for change)
Recommended: API GL-4gearoil (SAE
80W-90).
AIRCLEANER
Element
Removeframebodycover.
Remove6screwsfromthe air cleanercover.
Removeelement ofair cleaner(2screws).
Check the element ifdirt ordamaged.
Replaceit withnewone ifdirt ordamaged.
Caution
Inspect ifwasherisingood condition.
Replaceit withnewone ifit wasdef
ormed
ordamaged.
ŸAir cleanerelement containsapaper
made filtersodo not trytoclean it.
ŸMakesurethat the air cleanercover
had been installed properlyafter
installation.
Gear oil refillingbolt
Gear oil drainingplug
Screws
×
6
L..CINla.llA

2. MAINTENANCEINFORMATION
2-5
VALVE CLEARANCEADJUSTMENT
Caution
Removeluggageboxand front centercover.
Removethe left bodycover& left side cover.
Removecylinderhead cap.
Removethe ignition timingcheck holeon the
coolingfan cover.
With T”type wrench, turncrankshaft in
clockwisemotion sothat mark( T”)on the
generatorflywheelalignswiththe markon
the crankshaft, and camshaft isat TDC
position alsoassameaslevelofcylinder
head top-end.A singleholeon camshaft
sprocket isforwardtoup. (Piston isat TDC
position inthe compression stroke.)
Caution
VALVE CLEARANCEINSPECTION
AND ADJUSTMENT
Check & adjust valveclearancewithfeeler
gauge.
Valveclearance (IN/EX):
0.05±0.02 mm/0.10±0.02 mm
Loosen fixingnut and turnthe adjustment
nut foradjustment.
Caution
CARBURETORIDLESPEED
ADJUSTMENT
Caution
Checks and adjustment must be performed
when engine iscold(b
elow35℃).
The crankshaft can not be rotated in
counter-clockwisetoprevent fromdamage
sothat valveclearancecan not be
measured.
It hastomakesurethat valve-rocker
armis
be adjusted tostandardlevelwhen
adjustingit, and re-check the valve
clearanceaftertightened the fixingnut.
Ignition timing mark
ŸInspection & adjustment foridlespeed
havetobe performed afterall other
partsinengine that needed
adjustment havebeen adjusted.
ŸIdlespeed check and adjustment
havetobe done afterengine isbeing
warmup(around 10 minutes).
Aircleaner element
Ignition coil cable
Clearance
LCNlli..llA

2. MAINTENANCEINFORMATION
2-6
Parkthe motorcyclewithmainstand and
warnup engine.
Open the carburetorcoverfromthe luggagebox.
Turnthe throttlevalvestopperscrewto
specified idlespeed.
Specifiedidlespeed:1900±100 rpm
Emission adjustmentinIdlespeed
Warmup the engine foraround 10 minutes
and then conduct thisadjustment.
1. Connect the tachometerontoengine.
2. Adjust the idlespeed adjustment screw
and let engine runsin1900 100 rpm.
3. Insert the exhaust samplingmufflerof
exhaust analyzerintothe front section of
exhaust pipe. Adjust the air adjustment
screwsothat emission value inidlespeed
iswithinstandard.
4. Slightlyacceleratethe throttlevalveand
releaseit immediately. Repeat thisfor2~3times.
5.Read engine RPMand value on the
exhaust analyzer. Repeat step 2tostep 4
proceduresuntil measured value within
Euro4standard.
ExhaustEmission:CO: 1000mg/km
THC: 630mg/km
NOx: 170mg/km
SPARK PLUG
Appointedsparkplug:CR6HSA
Removeluggagebox.
Removecentercover..
Removesparkplugcap.
Clean dirt around the sparkplughole.
Removesparkplug.
Measuresparkpluggap.
Sparkplug gap:0.6~0.7mm
Carefullybend ground electrode ofthe plug
toadjust the gap ifnecessary.
Screwthe parkplugintothe plugholewith
hands, then tighten the plugwithawrenchto
prevent fromdamagingthe sparkplug's
thread.
Torquevalue:10~14 N.m
Connect sparkplugcap.
0.6~0.7mm
Side electrode Centerelectrode
Throttlevalvestopper screw
Airadjustmentscrew
LCINltii..llA

2. MAINTENANCEINFORMATION
2-7
CYLINDER COPMRESSION PRESSURE
Warnup engine and then turnoff the engine.
Removethe luggageboxand the center
Cover.
Removesparkplugcap and sparkplug.
Install compression gauge.
Full open the throttlevalve, and rotatethe
engine bymeansofsteppingthe
kick-startinglever.
Caution
Compression pressure:9.5 0.5bar.
Check followingitemsifthe pressureistoo
low:
lIncorrect valveclearance
lValveleaking
lCylinderhead leaking, piston, piston ring
and cylinderwornout
Ifthe pressureistoo high, it meanscarbon
depositsincombustion chamberorpiston
head.
DRIVINGSYSTEM
DRIVING BELT
Removeleft side cover.
Removemountingbolt located underair
cleaner.
Remove9boltsofthe engine left crankcase.
Removethe left crankcasecover.
Check ifthe belt iscrack orwornout.
Replacethe belt ifnecessaryorinaccord
withthe periodicalmaintenancescheduleto
replaceit.
Widthlimit:above17.2mm
Clutchpad
Start the motorcycleand graduallyincrease
throttlevalveopenness tocheck clutchpad
operation.
Ifthe motorcyclemoveswithshaking, then
check itsclutchpad forwearing.Replaceit
ifnecessary.
Rotatethe engine until the readinginthe
gaugeno moreincreasing.
Usually, the highest pressurereadingwill be
obtained in4~7seconds.
Gearteeth
Width
Clutch
Clutchpad
Spark plugcap

2. MAINTENANCEINFORMATION
2-8
Crankcase blow-byover-flowpipe
Replacementfor every1000km
1.Open the stopper
2.Drainthe oil
3.Install the stopper
Removedipstick tocheck the oil level. Ifoil
levelisbelowthe lowerlimit mark, add oil to
the specified upperlimit mark.
LONG-IIA

3. LUBRICATION SYSTEM
3-1
OILFLOWDIAGRAM........................ 3-1
GENERAL INFORMATION................ 3-2
TROUBLESHOOTING....................... 3-2
ENGINE OIL...................................... 3-3
CLEANING ENGINEOILSTRAINER...3-3
OILPUMP.............................................3-4
GEAROIL.............................................3-6
OILFLOWDIAGRAM
Valver
ocker
arm
Camshaft
Scooplubrication
Forcedlylubrication
Forcedly
lubrication
Innerpassage
Connectingrod
Oil pump
Oil strainer
Crankshaft
=- 08: ¥
LCNl:ii_JIA

3. LUBRICATION SYSTEM
3-2
GENERALINFORMATION
lThischaptercontainsmaintenanceoperationsforthe engine oil pump,engine oil and
gearoil.
Specifications
Engine oil quantityDisassembly800c.c.
Replacement 700 c.c.
Oil viscositySAE 15W-40orequivalent
UseSAE 5W-40when
outside temperatureis
below0 .
GearOil quantityDisassembly140c.c.
Replacement120 c.c.
Oil viscosityofgearoil SAE 80W-90(Recommend
API GL-4)
unit : mm
Items Standard Limit
Oil pump
Innerrotorclearance - 0.12
Clearancebetweenouter
rotorandbody - 0.12
Clearancebetweenrotor
side and body 0.05~0.10 0.20
Torquevalue
Engine oil drainplug20~26N.m
Engine oil filterscreen cap13~17N.m
Gearoil drainbolt10~15N.m
Gearoil fillingbolt10~15N.m
Oil pumpfixingscrews8~12N.m
TROUBLESHOOTING
Lowengineoillevel
lOil leaking
lValveguide orseatwornout
lPiston ringwornout
LowOil Pressure
lLowengine oil level
lClogged inoil strainer,circuitsorpipes
lOil pumpdamage
Dirtyoil
lNooil changeinperiodical
lCylinderhead gasket damage
lPiston ringwornout
Oil viscosity
LCJNl:ii_JIA
0
·20 - 10 0
10
20 30
40 C

3. LUBRICATION SYSTEM
3-3
ENGINEOIL
Turnoffengine,andparkthe motorcyclein
flat groundwithmainstand.
Check oil levelwithoil dipstick after3-5
minutes.
Donotrotatethedipstick intoengine as
checking.
If oil levelisnearlylowlevel, fill out
recommendedoil toupperlevel.
Oil Replacement
Caution
Placeanoil panunderthe motorcycle, and
removeoil strainercap.
Makesureif thealuminumwasherofthe
drainingbolt isdamaged. If so,replaceit
withnewone.
Install thedrainplugand tightenit.
Torquevalue:20~26 N.m
CLEANINGENGINEOILSTRAINER
Removetheoil strainercap.
Removeoil strainerandspring.
Clean oil strainer(recommendedusing
compressedair tocleandirtyforeign).
Check ifthe strainerand O-ringofthe oil
strainerarebroken. Replacewithnewoneif
found.
Install theoil strainerand spring.
Install theoil strainercap and tighten it.
Torquevalue:13~17 N.m
Fill out oil totheoil filler(Oil viscositySAE
15W-40)
UseSAE 5W-40when outside temperature
isbelow0 .
Engineoil quantity:Replacement700 c.c.
Drainoil asengine warmedupsothat
makesureoil canbedrained smoothlyand
completely.
oil strainer
spring
Dipstick
Oil drainplug
Oil strainercap
LCJNGi..JIA

3. LUBRICATION SYSTEM
3-4
OILPUMP
Oil Pump Removal
Removethealternator(refertochapter12).
Removetheengine right crankcasecover.
Makesurethat thepumpaxlecan berotated
freely.
Removetheoil pumpdrivinggearnut.
Removetheoil pump.
Oil Pump Inspection
Check theclearancebetween oil pumpbody
and outerrotor.
Limit:below0.12 mm
Check clearancebetween innerandouter
rotors.
Limit:below0.12 mm
-

3. LUBRICATION SYSTEM
3-5
Check clearancebetween rotorsideface
and pumpbody.
Limit:below2.0mm
Oil Pump Re-assembly
Install innerandouterrotorsintothepump
body.
Alignthe indent ondrivingshaftwiththatof
innerrotor.Install thedrivingshaft.
Install theoil pumpcoverandfixingpin
properlyand thentighten screw. (1screw)
Oil Pump Installation
Install accordingtothe reverseprocedureof
removal.
outerrotor
inner
rotor
Oil pumpbody
Oil
pump
cover
Driveshaft
Fixingpin
--= "" ~
LCNl:ii_JIA

3. LUBRICATION SYSTEM
3-6
GEAROIL
Oil Level Inspection
Parkthemotorcycleonflat groundwithmain
stand.
Turnoffengine and removebothgearoil
fillingboltandgearoil drainingplug.
Removegearoil fillingbolt and placea
measurement cupunderthe drainingplug.
Removetheoil draining plugand the pour
gearoil intothe measurement cup.
Measurethe gearoil quantityifwithin
standardvalue.
Add specifiedgearoil iftheoil leveltoolow.
Standardquantity: 140cc.
Replacement: 120cc.
GearOil Replacement
Removethegearoil fillingbolt and its
drainingplugandthendrainoil completely.
Install thedrainingplug and tightenit. (Make
sureiftheplugwasherisdamaged.Ifso,
replaceit withnewone.)
TorqueValue 10~15N.m
Add newgearoil (120 c.c.)fromthegearoil
fillingholeandtheninstall thegearoil filling
holeboltafteraddedoil.And then, tighten
the bolt.
TorqueValue:10~15N.m
※RecommendedtoapplywithSAE
80W-90. (RecommendAPI GL-4)
Startengine andrun itfor2~3minutes.
Turnoffengine and check ifoil leaking.
Gearoil drainingplug
0
LONm:..JtA

4.ELECTRONICALLYCONTROLLEDCARBURETORSYSTEM
4-1
ECS illustration ...................................4-1
Precautionsinoperation................... 4-2
General Information..........................4-3
ECSILLUSTRATION
-
=
LDNa.J_LA
( Bectro nically controlled
c. arbure· to r)
t Du tyf actor sole no id
va lv e)
( cata ly st )
(O xy gen
sensor )
ECU
(Al)
(E ng in e. $ peed sensor)

4.ELECTRONICALLYCONTROLLEDCARBURETORSYSTEM
4-
2
Item Specification
Main jet
Speed limited:45km/h 86#
Speed limited:25km/h 86#
Speed limited:30km/h 86#
Pilot Jet 33#
Needle Jet 2.1 mm
Levelin float chamber 21.5 0.5 mm
Float needle 1.6 mm
Mass offloat 7.2g 0.1 g
Idlespeed 2000 100 rpm
Fuelquantityadjustment screw 2 1/2 1/2
Jet needle 3r21
Throttle handle free play 2~6mm
Cautions
General Information
•Donotbend ortwist throttlevalvecable. Damaged cablewill makeunstabledriveability.
•When disassemblingfuelsystemparts,payattentiontoO-ringposition, replacewithnew
one asre-assembly
•Thereisadrainscrewinthefloat chamberfordrainingresidualgasoline.
•Donotdisassembleautomaticby-starterand air cut-offvalvearbitrarily.
Specification
Torque value
Fuelvalve tightening nut:1.5~2.0 Kgf-m
Tool
Special service tools
Vacuum/airpressure pump
Generalservice tools
Fuellevelgauge