Simplicity 1694851 Spécifications

HondaCG125OwnersWorkshopManualby Pete Shoemarkwith an additional Chapter on the 1985 on modelsby Jeremy ChurchillModels coveredCG125. 124cc. June 1976

'10Routine maintenancecapacity and place it beneath the engine unit to catch the oldoil. Unscrew the drain plug on the underside of the crankcase

100Chapter 6 Electrical systemFig. 6.8 Speedometer - early models (later models similar)/ Bulb(6v3w)2 Bulb(6v1.7w)-2off3 Speedometer assembly4 Mountin

Chapter 6 Electrical system10114.2 Horn is located here15.1 Main fuse holder clips to battery case15.2 Spare fuses should be kept in holder inside pan

102Chapter 6 Electrical system291322 20 22Fig. 6.9 Electrical system component parts - CGI 25, CG125 K1 and B models/2345678910GrommetCondenserDistanc

R.FRONT FLASHINGINDICATOR LAMPFLASHINGINDICATOR CONTROL-HORN SWITCH ARRANGEMENT IGNITION SWITCH ARRANGEMENTR(N)LwifecoiorWooGrR-oLBLo0FREEPUSHHOoLG/RE

FRONT RHANDIDICATOR LAMPSPEEDOME-£<! .LLUMMTMG JGn1HEADLIGHT OIMMER SWITCHFRONT L HANDFLASHING INDICATORLAMPf9999999 9! 9f ! B C»B- * - '1 • i

LIGHTING SWITCHNEUTRAL INDICATORSPEEDOMETER LIGHTSWITCH CONTINUITIGNITION SWITCHo-ooo-oo-oooooaoo"o-o-o-oONBA'O».fOEOFLASHING "HORN-DIM

106The CG125 (BR)-E/F modelThe CG125 (BR)-J model

Chapter 7 The 1985 on modelsContentsIntroduction 1Routine maintenance: schedule modifications 2Routine maintenance: changing the engineoil - CG125(BR)

108Chapter 7 The 1985 on modelsCylinder boreGasket surface maximum warpage 0.100 mm (0.0039 in)Piston to cylinder clearance 0.010 - 0.040 mm (0.0004 -

Chapter 7 The 1985 on models109Torque wrench settingsComponent kgf m Ibf ftPetrol tap filter bowl 0.3 - 0.5 2 - 3.5Engine oil drain plug (where fitted

Routine maintenance11Checking the condition of the contact breaker pointsThe contact breaker assembly can be viewed through oneof the generator rotor

110Chapter 7 The 1985 on modelsTyres FrontSizes:CG125(BR)-E/F and J models 2.75 - 18 42PCG125(BR)-K model 2.75 - 18 42PPressures - tyres cold:Solo 25

1.7a Chain enclosure is secured bythree bolts at the rear on BR-E/F andBR-J models ...1.7b ... and by two bolts at the rear on 1.7c Note later type of

112Chapter 7 The 1985 on models2 Routine maintenance: schedule modifications1 With reference to the Routine maintenance section at thefront of this ma

Chapter 7 The 1985 on models113machine so that the brake components can then be dismantled,cleaned, checked for wear, and reassembled. It is important

114Chapter 7 The 1985 on modelsmachines and can be easily obtained from a good motorcycledealer.2 Note that the piston crown marking mentioned in Chap

Chapter 7 The 1985 on models1152 Unscrew the three retaining screws to release the pumpcover from the base of the float bowl. Withdraw the cover,notin

13.1a Float bowl can be removedcomplete with pump assembly13.1b Do not dismantle acceleratorpump linkage unless absolutleynecessary13.2a Pump cover is

Chapter 7 The 1985 on models11714 (T)PFC carburettor: refittingBrazilian modelsCG125-C. E and1 Refit the throttle valve assembly ensuring that the gro

118Chapter 7 The 1985 on models17 Condenser: general1 Note that while the condenser is mounted as described inChapter 3, it is no longer listed as a s

Chapter 7 The 1985 on models1195 Remove the damper rod Allen bolt. If this has broken freefrom the lower leg but will not unscrew from the damper rod,

12Routine maintenanceand close the throttle several times, allowing it to snap shutunder its own pressure. Ensure that it is able to shut off quicklya

120Chapter 7 The 1985 on models21 Front fork legs: reassembly1 On reassembly, all components should have been checkedfor wear and renewed as necessary

Chapter 7 The 1985 on models12124.3 Press latch on each side to releaseseat (tail fairing will obscure latches onBR-K model)24.5a Remove grab rail (fo

IS)1 Wheel spindle2 Washer - 2 off3 Spacer4 Oil seal5 Bearing - 2 off6 Nut-4 off7 Hub flange8 Stud - 4 off9 SpacerFig. 7.4 Front wheel and brake10 Bra

Chapter 7 The 1985 on models 12327 Brakes: overhaul1 When overhauling the brakes check that the brake operat-ing cam is working smoothly and is not bi

FRONT RIGHT-HAND ( I IPLASHING INDICATOR \ I 1LAMF N—'NEUTRAL INDICATORNIGH BEAM INDICATORMETER LIGHTAD LAMP ( rG-P1LOT LAMPFRONT LEFT-HAND f 1 I

Conversion factorsli.Length (distance)Inches (in)Feet (ft)MilesVolume (capacity)Cubic inches (cu in; in3)Imperial pints (Imp pt)Imperial quarts (Imp q

126IndexAcknowledgements 2Adjustmentsbrakes 12, 83,86, 112carburettor 54, 117clutch 12contact breaker points 10, 61final drive chain 9, 87ignition tim

127'Decarbonising 34Dimensions 5, 107Dualseat78, 121Electrical systembattery 9, 95charging system 94check 93fault diagnosis 102flashing indicator

128hParts - ordering 6Pedal - rear brake 77Petrolpipe 52tank 52, 114tap 53Pistonexamination and renovation 31modifications 113refitting 46removal 19Pr

Routine maintenance132 Clean the centrifugal oil filterRemove the crankcase right-hand cover, as described inChapter 1.10, then remove its three retai

Working conditions and toolsWhen a major overhaul is contemplated, it is important thata clean, well-lit working space is available, equipped with awo

Chapter 1 Engine, clutch and gearboxRefer to Chapter 7 for information relating to the 1985 on Brazilian modelsContentsGeneral description 1Operations

16 Chapter 1 Engine, clutch and gearboxPiston rings : 2 compression, 1 oil scraperRing to groove clearanceTop 0.03-0.05 mm (0.0012-0.0020 in)2nd 0.02-

Chapter 1 Engine, clutch and gearbox17GearboxReduction ratiosPrimary drive1st2nd3rd4th5thFinal driveSelector fork claw end thickness ...Wear limitSele

18Chapter 1 Engine, clutch and gearboxpacking pieces behind it. The exhaust is secured by two nuts toits mounting bracket, which is secured to the fra

Chapter 1 Engine, clutch and gearbox195.6b ... rear mounting nuts to release complete exhaust system 5.7 Release the locking plate to permit sprocket

AcknowledgementsOur thanks are due to APS Motorcycles of Wells (formerlyFran Ridewood & Co), Paul Branson Motorcycles of Yeovil, andCSM of Taunton

20Chapter 1 Engine, clutch and gearboxspark plug lead, the exhaust pipe and the cylinder head steadybolt, as described in Section 5 of this Chapter.2

2124Fig. 1.2 Cylinder head and barrel - component parts/2345678910Inlet valve guideExhaust valve guideCylinder barrelCylinder base gasketCylinder head

r22Chapter 1 Engine, clutch and gearbox7.2c Withdraw the pushrods, noting which is inlet and exhaust7.4a Slide barrel carefully off its studs7.3 Note

Chapter 1 Engine, clutch and gearbox23generator components. The central retaining nut should betemporarily refitted so that it is flush with the shaft

9.2a Note thrust washer when removing cam gear shaft 9.2b Lift out the cam gear/cam unitI10.3 Home-made peg spanner is crude but proved effective 10.4

Chapter 1 Engine, clutch and gearbox2512 Dismantling the engine/gearboxclutch assembly and crankshaft pinionunit: removing the1 Lift out the clutch pu

12.1a Remove the pushrod and pushrod seat12.1b Lift away the thrust plate after releasing bolts012.2a Remove the circlip to allow ...12.2b ... outer h

Chapter 1 Engine, clutch and gearbox271 2.2e Crankshaft pinion can be slid off splined crankshaft end13.1 Disengage gearchange shaft and withdraw from

28Fig. 1.6 Crankshaft and piston1 Crankshaft assembly2 Piston ring set3 Piston4 Gudgeon pin5 Connecting rod6 RH flywheel7 LH flywheel8 Crankpin9 Cam d

14.1 End-float plunger is retained by a single bolt14.2 Neutral indicator switch is easily withdrawn16.1a Disengage and remove the kickstart mechanism

ContentsAcknowledgementsAbout this manualIntroduction to the Honda CG125Model dimensions and weightOrdering spare partsSafety first!Routine maintenanc

r30Chapter 1 Engine, clutch and gearbox1 6.3a Lift out mainshaft and layshaft clusters complete17.1a Clean cases thoroughly and check bearings etc17.2

Chapter 1 Engine, clutch and gearbox31A certain amount of side play is intentional, and should bebetween 0-05 - 0-30 mm (0-002 - 0012 in) on a new cra

32Chapter 1 Engine, clutch and gearbox5 Piston ring wear is measured by removing the rings fromthe piston and inserting them in the cylinder bore usin

23.1a Compress springs and prise out collet halves, torelease ...23.1b ... the top spring seat .23.1 c ... and valve springs23.1d Note lower outer spr

34Chapter 1 Engine, clutch and gearbox24 Examination and decarbonisation: cylinder head1 Remove all traces of carbon from the cylinder head andvalve p

Chapter 1 Engine, clutch and gearbox354 Measure the uncompressed length of the clutch springswhich should be 35.5 mm (1-398 in) when new. Should anysp

36Chapter 1 Engine, clutch and gearbox2 Fit the neutral switch contact to the end of the selectordrum, and then lower it, contact downwards, into the

3732.2f Slide 2nd gear pinion (1 7T) into position32.2g Slide shim and sleeve gear onto other end of shaft32.2h Place 4th gear pinion (27T) in positio

32.21 Fit kickstart pinion (also bushed)32.2m Note: If layshaft has this circlip groove, it must beignored. Do not fit circlip32.2n Slide 5th gear pin

33.1 Lower fork is retained by spring-loaded ball33.2b Place gearbox components into left-hand casing33.2a Do not omit the neutral switch contact duri

The Honda CG125 modelThe Honda CG125-C model

40Chapter 1 Engine, clutch and gearbox34 Preparation of crankcase jointing surfaces: joining thecrankcase1 Coat the jointing surfaces of both crankcas

35.2a Detent roller arm is retained by a shouldered bolt 35.2b Note locating pin which engages in camplate35.2c Fit camplate and tighten bolt35.2d If

42Chapter 1 Engine, clutch and gearbox36 Replacing the clutch assembly and centrifugal oil filter1 Place the clutch outer drum in position on the gear

36.2b Position springs over threaded pillars/P.36.3a Slide on the inner half of centrifugal filter36.2c Fit pressure plate and pushrod and cup36.3b No

44Chapter 1 Engine, clutch and gearbox36.3e Fit new gasket and replace the cover37 Replacing the camshaft, generator and left-hand casingfittings1 Tur

37.2b ... aligning the timing marks as shown37.3a Do not omit thrust washer or small spring whenrefitting cam gear shaft37.3b Depress end float plunge

46Chapter 1 Engine, clutch and gearbox39 Refitting the piston, cylinder barrel, cylinder head androcker arms1 Raise the connecting rod to its highest

Chapter 1 Engine, clutch and gearbox4739.7a Fit new head gasket. Note position of dowels 39.7b Ensure that pushrods engage in cam followers correctly3

48Chapter 1 Engine, clutch and gearboxensuring that all gaskets and/or O-rings are renewed ifnecessary, that all components are refitted the correct w

40.3a Push breather pipe over crankcase stub40.3b Reconnect clutch cable, and check adjustment40.3c Refit the carburettor, noting guide for HT cable40

Introduction to the Honda CG125The CG125 model first appeared in the UK in June 1976. Itcan be regarded in many ways as a utility version of the popul

50Chapter 1 Engine, clutch and gearbox41 Starting and running the rebuilt engine1 Make a final check around the engine to ensure thateverything has be

Chapter 1 Engine, clutch and gearbox51SymptomCause RemedyNoisy engineEngine noiseSmoking exhaustInsufficient powerOverheatingTappet noise:Excessive ta

Chapter 2 Fuel system and lubricationRefer to Chapter 7 for information relating to the 1985 on Brazilian modelsContentsffGeneral descriptionPetrol ta

Chapter 2 Fuel system and lubrication532.2 Rubber strap retains rear of petrol tank4 Petrol tap: removal, repair and replacement1 Before the petrol ta

54Chapter 2 Fuel system and lubrication5.3a Remove carburettor body from inlet port5.3b It is not normally necessary to remove heat shieldcarburettor

Chapter 2 Fuel system and lubrication55Fig. 2.1 Carburettor -077A type1 Gasket set2 Needle valve assembly3 Needle jet4 Float assembly5 Mixing chamber

6.3a Main jet can be unscrewed for cleaning .6.3b ... as can the jet holderFig. 2.2 Carburettor - PD88E type6.4 Pilot screw is located here — later ty

Chapter 2 Fuel system and lubrication577.2 Adjust idle speed by means of this screw10 Air cleaner: removal, cleaning and replacement ofelements1 Pull

12.2a Note alignment marks on oil pump components 12.2b Casing is secured by two bolts, and can be removed ...12.2c ... to allow pinion ...12.2d ... a

Chapter 2 Fuel system and lubrication5914 Fault diagnosis: fuel system and lubricationSymptomCause RemedyExcessive fuel consumptionIdling speed too hi

Ordering spare parts*When ordering spare parts for the CG125 models, it isadvisable to deal direct with an official Honda agent, who willbe able to su

Chapter 3 Ignition systemRefer to Chapter 7 for information relating to the 1985 on Brazilian modelsContentsGeneral descriptionGenerator : checking th

Chapter 3 Ignition system61IGNITION COIL CONDENSERSPARK PLUGCONTACT BREAKERFig. 3.2 Ignition system: component location3 Contact breaker: adjustment1

62Chapter 3 Ignition system3.1 Automatic timing unit in flywheel rotor may be lubricatedlightly3.3 Check contact breaker gap using feeler gaugei4.3 Fl

Chapter 3 Ignition system63and battery arrangement connected as shown in theaccompanying diagrams. Should any of these checks notproduce the expected

64Bulb should not lightBFig. 3.4 Condenser: test sequenceA: Using a battery/bulb arrangementB: Using a multimeter6V10-20WBulb should not light.Bulb sh

Electrode gap check - use a wire type gauge for best resultsElectrode gap adjustment - bend the side electrode using thecorrect toolNormal condition -

DO9 Fault diagnosisSymptom: ignition systemCauseChapter 3Ignition systemRemedyEngine will not startEngine starts but runs erraticallyPlug faultyDefect

Chapter 4 Frame and forksRefer to Chapter 7 for information relating to the 1985 on Brazilian modelsContentsGeneral description 1Front forks : removal

68Chapter 4 Frame and forks2 Front forks: removal — general1 It is unlikely that the forks will require removal from theframe unless the fork seals ar

Chapter 4 Frame and forks693.2 Remove fork top bolt to release yoke4 Front forks: removing the fork legs from the yokes1 It is not necessary to remove

Safety first!Professional motor mechanics are trained in safe workingprocedures. However enthusiastic you may be about getting onwith the job in hand,

70'>.7 Reflector - 2 off2 Seat - 2 off3 Right-hand fork assembly4 Fork spring - 2 off5 Spring guide — 2 off6 Stanchion7 Lower leg8 Sleeve -2 o

Chapter 4 Frame and forks71diameter measured and compared with the figures given in theSpecifications section of this Chapter. Play between the lowerb

k7.4b ... and lower, plain bush, for wear7.6a Note the position of spring rings ...7.6b ... which locate the bushes on the stanchion7.6c Do not omit r

Chapter 4 Frame and forks737.6f Do not omit the screw in base of lower leg, wherenecessary8 Fork legs: dismantling, examination and renovation -CG125

74Chapter 4 Frame and forksVFig. 4.3 Frame - component parts1110 Frame assembly: examination and renovation1 If the machine is stripped for a complete

1 1.4a Slacken and remove pivot shaft nut75Fig. 4.4 Front forks - CG125 K1 and later models1 Top bolt2 O-ring3 Washer4 Dust seal5 Stanchion6 Circlip7

76Chapter 4 Frame and forks1 1.5 Bushes can be pressed out if worn1 1.6 Check that torque arm mounting is secure1 1Fig. 4.5 Swinging arm and chain enc

Chapter 4 Frame and forks77Fig. 4.6 Rear suspension units7 Suspension unit - 2 off2 Damper - 2 off3 Rubber bush4 Metal sleeve5 Domed nut - 2 off678910

78Chapter 4 Frame and forks16 Speedometer head: removal and replacement1 The speedometer is secured to a bracket that bolts to thetop yoke, on which t

21 Fault diagnosis:Symptomframe andforksCauseChapter 4Frameandforks /»RemedyMachine veers either to the leftor the right with hands offhandlebarsMachi

Routine maintenanceRefer to Chapter 7 for information relating to the 1985 on Brazilian modelsIntroductionPeriodic routine maintenance is a continuous

Chapter 5 Wheels, brakes and tyresRefer to Chapter 7 for information relating to the 1985 on Brazilian modelsContents.General description 1Front wheel

Chapter 5 Wheels, brakes and tyres813 Front wheel: removal1 With the machine supported on the centre stand, block thestand and crankcase to raise the

3.2 Detach the speedometer and brake cables3.3 Withdraw the wheel spindle, and lower the wheel clear4.1 a Brake plate assembly can be lifted out of dr

Chapter 5 Wheels, brakes and tyres834.7 Align punch marks to ensure operating arm is refittedcorrectly on brake camshaftadjusted by removing the opera

84Chapter 5 Wheels, brakes and tyres8 Rear wheel: examination1 Place the machine on the centre stand and before removingthe rear wheel, follow the pro

Chapter 5 Wheels, brakes and tyres853 Remove the spring pin which retains the torque arm nut,then remove the nut and disengage the torque arm from the

86Chapter 5 Wheels, brakes and tyresFig. 5.2 Rear brake - component parts1 Drawbolt2 Rear wheel spindle3 Spacer4 Brake plate5 Cam6 Actuating lever7 Ru

Tyre changing sequence - tubed tyresDeflate tyre. After pushing tyrebeads away from rim flangespush tyre bead into well of rimat point opposite valve.

11.2b New bearings must be fitted if worn11.2c A large socket makes a useful drift11.2d New seals should be fitted together with bearings 12.1a Sprock

Chapter 5 Wheels, brakes and tyres8916Fig. 5.3. Rear wheel and hub - component parts/ Drawbolt2 Rear wheel sprocket3 Bonded rubber bush -4 off4 Dust c

Routine maintenance4Check the tyre pressures and tread wearCheck the tyre pressures with a gauge that is known to beaccurate. It is worthwhile purchas

14.2a Plug can be removed for lubrication and chain tensioncheck14.2b Ensure that drain holes remain clear- unblockif necessary14.4 Marks ensure corre

Chapter 5 Wheels, brakes and tyres9115 Rear wheel: replacement1 Clean and grease the rear wheel spindle, check that thesprocket and dust cover have be

192Chapter 5 Wheels, brakes and tyres17 Fault diagnosis: wheels, brakes and tyresSymptomCauseRemedyIneffective brakesHandlebars oscillate at low speed

Chapter 6 Electrical systemRefer to Chapter 7 for information relating to the 1985 on Brazilian modelsContentsGeneral description 1Checking the electr

94Chapter 6 Electrical system3 Charging system: checking the output1 A defect in the charging system will produce poorheadlamp performance, and probab

Chapter 6 Electrical system95Green/red BlackPinkPoints opened.Fig. 6.2 Checking the generator stator1818Fig.and;234567891011121314151617181920216.3 Fl

Chapter 6 Electrical systemBattery charging instructionsNormal chargeRapid chargeCharging current rate• Checking for full chargeCharging durationRemar

Chapter 6 Electrical system974.1 Rectifier is rubber-mounted to battery carrierand twist it anticlockwise to release it. On CG125-C and Emodels twist

9811Fig. 6.6 Headlamp unit- CG125. CG125 K1 and B models1 Rim2 W-clip - 4 off3 Screw4 Washer5 Reflector6 Headlamp bulb7 Bulbholder8 Pilot lamp bulb*9

Chapter 6 Electrical system99wr6.7 Note how W-clips are fitted beforedisturbing them7.2 Tail lamp lens is retained by twoscrews8.1 Brake switch can be