BSA D14/4 BANTAM SUPREME D14/4 BANTAM SPORTS Workshop Manual Download

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D14/4

ENGINE

INDEX

Page

DESCRIPTION

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OPERATION OF THE TWO-STROKE ENGINE

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DECARBONISING:

Silencer

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Removal of Cylinder

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Piston

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Piston Rings

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Cylinder Head and Barrel

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Small-end Bearing

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Big-end Bearing

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Reassembly after Decarbonising

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REMOVAL OF ENGINE . .

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ENGINE DISMANTLING . .

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CLUTCH PLATE DISMANTLING

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GEARBOX DISMANTLING

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B10

REMOVAL OF CLUTCH HUB . .

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B11

GEARBOX INSPECTION . .

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B11

ATTENTION TO FLYWHEELS . .

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B12

ENGINE REBUILDING

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B14

IGNITION TIMING:

Contact Breaker Gap

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B17

Piston Position

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B18

Setting the Timing

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B18

CLUTCH ADJUSTMENT . .

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B19

Summary of Contents for D14/4 BANTAM SUPREME D14/4 BANTAM SPORTS

Page 1: ...WORKSHOP MANUAL for D14 4 models BANTAM SUPREME BANTAM SPORTS BUSHMAN Service Department Telephone 021 772 2381 B S A MOTOR CYCLES LTD ARMOURY ROAD BIRMINGHAM 11 Publication Reference 00 4152 4 69 ...

Page 2: ...Please Note Replacement parts or accessories must be of B S A origin or as approved by B S A Motor Cycles Ltd In this respect your attention is drawn to the Terms and Conditions of B S A Guarantee ...

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Page 6: ...e useful to the inexperienced mechanic but it will also serve as a reference book for the skilled mechanic The information given in this manual is correct at the time of publication but in the course of constant development it is inevitable that there will be changes in specification Anyone finding the information given in this manual to be at variance with the machine in his possession is advised...

Page 7: ...hat Service Department attention is required he will know best how to make suitable arrangements with the factory It is important to remember that no machine can be accepted at the works without a prior appointment This appointment can be made either by letter or telephone Labour time will be greatly reduced if proprietary articles such as legshields safety bars carriers or fibre glass fairings ar...

Page 8: ...ufacturers concerned CARBURETTERS Amal Limited Holdford Road Witton BIRMINGHAM 6 CHAINS Renold Chains Limited Wythenshawe MANCHESTER ELECTRICAL EQUIPMENT Wipac Group Sales Limited London Road BUCKINGHAM Joseph Lucas Limited Gt Hampton Street BIRMINGHAM 18 REAR DAMPERS Girling Limited Birmingham Road WEST BROMWICH Staffs SPARK PLUGS Champion Sparking Plug Co Ltd Feltham MIDDLESEX SPEEDOMETERS Smith...

Page 9: ...lp when repairs are needed Labour time will be greatly reduced if proprietary articles such as legshields crash bars carriers or fibre glass fairings are removed before handing the machine over for repair Accessories such as mirrors or badges should always be removed before entrusting a machine to an independent carrier TECHNICAL ADVICE The B S A Service Department staff at the two U S A factory b...

Page 10: ... to 6 ENGINE B 1 to 19 CARBURETTER C 1 to 8 FRAME AND FITTINGS D 1 to 12 FRONT FORKS E 1 to 9 WHEELS BRAKES AND TYRES F 1 to 12 ELECTRICAL EQUIPMENT G 1 to 15 CHAINS H 1 to 3 TORQUE WRENCH SETTINGS J 1 SERVICING TOOLS K 1 to 4 CONVERSION TABLES L 1 to 10 Page 10 ...

Page 11: ...ter GD3 Bearing Dimensions GD4 TRANSMISSION Clutch GD4 Sprockets GD4 Chain Size GD4 Gear Ratios GD5 FRAME AND FITTINGS Front Forks GD5 Rear Dampers GD5 Swinging Arm GD5 Bushes GD5 WHEELS BRAKES AND TYRES Wheels GD6 Wheel Bearings GD6 Brakes GD6 Tyres GD6 ELECTRICAL EQUIPMENT GD6 CAPACITIES GD7 BASIC DIMENSIONS GD7 WEIGHTS GD7 Page ...

Page 12: ...MENSIONS GD8 WEIGHT GD8 BUSHMAN MODELS ENGINE Bearing Dimensions GD9 Forks GD9 Carburetter GD9 TRANSMISSION Gear Ratios GD9 Chain Sizes GD9 BUSHMAN PASTORAL MODELS TRANSMISSION Gear Ratios GD9 Sprockets GD9 Chain Sizes GD9 WHEELS BRAKES AND TYRES Wheels GD9 Tyres GD10 ELECTRICAL EQUIPMENT GD10 BASIC DIMENSIONS GD10 WEIGHTS GD10 ...

Page 13: ... Fitted gap maximum 013 3302 mm Fitted gap minimum 009 2286 mm CYLINDER BARREL Material Close grained cylinder iron Bore size standard 61 5 mm Stroke 58 mm Oversizes 020 040 508 mm 1 016 mm Inlet port size 1 25 4 mm Exhaust port size 1 32 mm IGNITION TIMING Fixed Crankshaft before top dead centre 16 5º Piston before top dead centre 0 060 1 524 mm CARBURETTER Concentric Type Amal R626 12 Main jet 1...

Page 14: ...08 mm Gearbox mainshaft bearing 625 1 5625 4735 15 875 39 6875 11 1125 mm Big end roller 18 4 8 mm Small end bearing 5625 75 625 14 2875 19 05 15 875 mm Gudgeon pin diameter 5617 5620 14 267 14 275 mm TRANSMISSION CLUTCH Type Multi plate Number of plates 7 Driving bonded segments 4 Driven plain 3 Overall thickness of driving plates and segments 3 mm Clutch springs 6 Free length of springs 1 9 64 2...

Page 15: ... 1 122 28 473 28 499 mm Upper bush bore 1 058 1 059 26 873 26 899 mm Working clearance 0 013 0 330 mm Lower bush outer diameter 1 118 1 119 28 397 28 425 mm Lower bush bore 1 000 1 001 25 4 25 425 mm Working clearance 0 006 0 011 0 152 0 279 mm Length upper and lower 1 25 4 mm REAR DAMPERS Type Coil spring hydraulically damped Springs fitted length 5 7 144 78 mm spring rate 100 lb in colour identi...

Page 16: ...and 5899 5904 14 9835 14 9962 mm Rear left and right hand 17 40 12 mm Spindle diameter at ground portions 6687 6692 16 985 16 998 mm BRAKES Front and rear diameter 5 139 7 mm Front and rear width 1 25 4 mm Lining thickness 5 32 4 mm Total lining area front and rear 20 sq in 129 sq cm TYRES Size front and rear 3 00 18 Pressure front 17 p s i 1 2 atm Pressure rear 22 p s i 1 5 atm see also page F12 ...

Page 17: ... litre Front fork each leg pint 0 07 litre BASIC DIMENSIONS Wheelbase 50 0 127 cm Overall length 77 5 196 85 cm Handlebar width 27 75 70 49 cm Seat height unladen 31 78 74 cm Overall height approximate 40 0 101 6 cm Ground clearance 6 75 17 15 cm WEIGHTS Machine unladen 215 lbs 97 5 kg Engine gearbox unit less carburetter 51 lbs 23 kg ...

Page 18: ...251 31 750 31 775 mm Working clearance 0 001 0 003 0 025 0 076 mm Length 2 overall 28 5 mm Lower bush outside diameter 1 473 1 474 37 44 37 41 mm Lower bush bore 1 2485 1 2495 31 714 31 737 mm Working clearance 0 001 0 004 0 025 0 102 mm Length 1 overall 31 75 mm WHEELS Spoke sizes front left hand 12 s w g 6 21 32 2 641 169 069 mm rear right hand 10 s w g 6 9 16 3 251 166 687 mm BASIC DIMENSIONS S...

Page 19: ...s TRANSMISSION D14 Bushman Pastoral models GEAR RATIOS Gearbox As Bantam Supreme models Overall top 8 10 1 third 10 54 1 second 14 83 1 first 23 03 1 SPROCKETS Rear wheel 58 teeth CHAIN SIZES Transmission 500 0 205 126 links WHEELS BRAKES AND TYRES WHEELS Rim size and type front WM1 19 Rim size and type rear WM2 19 Spoke size front left hand 12 s w g 8 2 641 225 42 mm front right hand inner 12 s w...

Page 20: ...Contact breaker unit Wipac S0584 Ignition coil Lucas 3E T Bulbs headlight main 24 24 watt pre focus The battery rectifier headlight pilot bulb and horn are not fitted to these models BASIC DIMENSIONS Overall length 78 198 cm Handlebar width 28 5 72 cm Seat height unladen 30 5 77 5 cm Ground clearance 10 25 cm Overall height approximate 40 5 103 cm WEIGHT Machine unladen 222 lbs 100 5 kg ...

Page 21: ...AKER A4 CONTROL CABLES A6 ENGINE LUBRICATION A3 FRONT FORK A5 GEARBOX LUBRICATION A3 REAR CHAIN A4 REAR SUSPENSION A6 RECOMMENDED LUBRICANTS A3 ROUTINE MAINTENANCE A2 SPEEDOMETER CABLE A6 STEERING HEAD A4 WHEEL BEARINGS A5 CLEANING AND POLISHING A6 ...

Page 22: ...eadings in later chapters FIG A1 Ref No Ref No Weekly Every 2 000 miles 3 200 km 7 Oil brake pedal pivot 2 Change oil in gearbox 9 Oil exposed cables and control joints 6 Grease brake cams Every 5 000 miles 8 000 km 11 Grease speedometer drive cable Every 1 000 miles 1 600 km 4 Lubricate contact breaker cam 2 Check oil level in gearbox 5 Grease swinging arm pivots 2 Every 10 000 miles 16 000 km 3 ...

Page 23: ... mixture ENGINE LUBRICATION The lubrication of the engine is provided by the oil mixed with the petrol supply forming a mixture commonly known as petroil The correct proportion of oil to petrol is given on this page For efficient running of the engine and adequate lubrication it is essential that the oil be completely mixed with the petrol It is preferable to use one of the self mixing two stroke ...

Page 24: ...ted behind the contact plate Periodical lubrication of the contact breaker cam however is necessary Provision is made for this in the form of a grease soaked wick The grease preferably of the high melting point type should be applied sparingly to the wick every 5 000 miles 8 000 km Avoid using the grease excessively otherwise the contact points may become contaminated resulting in misfiring and di...

Page 25: ...a few times to expel any remaining oil in the system Repeat the operation on the other fork leg and replace the drain studs and new fibre washers Pour an eighth pint of an S A E 20 oil into each fork leg and replace the top nuts and caps FRONT FORK Sports and Bushman The procedure for draining and refilling the forks fitted to the D14 4 Sport and Bushman is much the same as above except that the f...

Page 26: ...NOTE Should the damper bushes become noisy and squeaky do not lubricate them with oil A small quantity of hydraulic brake fluid will be found to be most effective and will not harm the rubber bushes The swinging arm pivot is provided with grease nipples and must be thoroughly lubricated every 1 000 miles CLEANING AND POLISHING Regular cleaning and polishing will protect the finish of the motor cyc...

Page 27: ...rel B6 Small end Bearing B6 Big end Bearing B7 Reassembly after Decarbonising B7 REMOVAL OF ENGINE B7 ENGINE DISMANTLING B8 CLUTCH PLATE DISMANTLING B9 GEARBOX DISMANTLING B10 REMOVAL OF CLUTCH HUB B11 GEARBOX INSPECTION B11 ATTENTION TO FLYWHEELS B12 ENGINE REBUILDING B14 IGNITION TIMING Contact Breaker Gap B17 Piston Position B18 Setting the Timing B18 CLUTCH ADJUSTMENT B19 ...

Page 28: ...D14 4 ENGINE B2 FIG B1 Engine exploded ...

Page 29: ...ke leaving the exhaust port completely uncovered to enable the burnt gases in the cylinder to escape through the exhaust system The transfer ports are also open allowing the compressed mixture in the crankcase to force its way into the cylinder Each transfer port only one is shown in the diagram is so arranged that the stream of incoming mixture is directed to the rear of the combustion chamber As...

Page 30: ...en via the primary chain to the clutch assembly Here the transmission is controlled by a series of spring loaded friction plates before passing through the four speed constant mesh gearbox to the gearbox sprocket DECARBONISING Internal combustion of the petroil mixture in the engine produces normal carbon deposits on the piston crown rings cylinder head and ports These deposits are not harmful pro...

Page 31: ...hickness when fitting as two must be fitted if of the thinner type Before attempting to remove the cylinder barrel first unscrew the two petrol tank front fixing bolts loosen the rear fixing bolt and raise the tank slightly to provide sufficient clearance The petrol tank on the Bushman models must be removed completely Care must be taken when sliding the barrel off the studs to support the piston ...

Page 32: ... peg in the groove This can be checked by closing the ring in the groove until the gap closes proving that there is clearance at the peg below If the gap cannot be closed indicating that the steps are binding on the peg use a smooth file to ease the steps down It is advisable to check the gap of a new ring before fitting and if the gap is found to be less than 0 07 1778 mm the ends of the ring mus...

Page 33: ... the front Before fitting the gudgeon pin smear it with oil and do not forget to replace the circlips Remember that if the circlips should come adrift or if one is omitted the cylinder barrel may be seriously damaged Before attempting to replace the cylinder barrel over the piston smear the piston sides generously with clean engine oil Fit a new gasket and place the barrel over the piston carefull...

Page 34: ...e out of the frame When a prop stand has been fitted as an optional extra not applicable to Bushman models it will be released on removal of the front fixing bolts On Bushman models the front fixing bolts also retain the crankcase shield The kickstart and gearchange pedals can now be taken off in preparation for engine dismantling described below ENGINE DISMANTLING Perfect cleanliness is essential...

Page 35: ...h of chain unscrew the nut Pass a length of bar through the small end bearing and taking care not to damage the crankcase top joint face turn the engine until it is locked solid FIG B8 The generator rotor is secured to the keyed engine shaft by one large nut and spring washer Undo this pull off the rotor and extract the Woodruff key from the shaft Using the same method remove the self locking nut ...

Page 36: ...is easily damaged After removing the sprocket tap out the small Woodruff key and take off the rubber oil seal and steel collar The crankcases are now about ready for splitting First take out the twelve Phillips head screws from around the outer edge of the case on the generator side two of which are to be found below the cylinder barrel flange and then remove the four screws from around the gearbo...

Page 37: ...ntre pinion thrust bearing and two washers and the clutch chainwheel The kickstarter ratchet pinion is held on to the chainwheel by a circlip which when removed releases the pinion spring and retainer The gearbox mainshaft complete with its fixed first gear and third gear can now be withdrawn GEARBOX INSPECTION The mainshaft third gear is held against the mainshaft first gear by a circlip This gea...

Page 38: ...The bearing is of ample dimensions for the work it has to do and provided that the engine has been carefully used and adequately lubricated the bearing is unlikely to need replacement If the bearing has noticeably deteriorated as the result of neglect or abuse the flywheels must be parted to gain access to the bearing The flywheels are a press fit on to the ends of the crankpin and no attempt shou...

Page 39: ... actual or similar bearings used in the engine should be fitted to the shafts and the assembly mounted in vee blocks as shown in Fig B15 Using a dial micrometer measure the accuracy of the assembly Any necessary should be made by the careful use of a mallet or lead hammer The wheels should be brought within the limit of 004 on the rims 006 on the inner faces and a maximum of 002 on the shafts FIG ...

Page 40: ...ps and can therefore only be knocked out from one side Whenever the engine is stripped it is advisable to replace all oil seals ENGINE ASSSEMBLY Fit the gearbox mainshaft through its bearing in the right hand crankcase and grip the mainshaft in a soft jawed vice Assemble the clutch drum and kickstart ratchet pinion having first checked the ratchet teeth for signs of wear The kickstarter ratchet en...

Page 41: ... side of the engine place the kickstart in position Fit the clock type spring on to the kickstarter quadrant shaft and the circular distance plate between the case and the spring Give the spring one turn of tension and push the kickstarter quadrant home in its recess with the quadrant against its stop below the dowel hole Replace the dowel to stop the quadrant unwinding the spring Replace the gear...

Page 42: ...d and held in position with one screw at the rear and a solid dowel at the front FIG B20 Fit the distance pieces over each generator stud and replace the stator The stator is correctly fitted when the cable assumes a three o clock position and is outward Replace the fixing nuts with their spring washers noting that the special nut is fitted at the front It is essential that the air gaps between th...

Page 43: ... are centrally located in the elongated holes to allow for adjustment either way Refit the cam on the shaft but do not fully tighten the screw Engine assembly from this point should proceed as detailed in Reassembly after decarbonising on page B7 IGNITION TIMING Contact Breaker Gap In order to maintain correct ignition timing the contact points must be set to the specified gap when in the fully op...

Page 44: ... very difficult to find It is a good point therefore to use a suitable stop such as a dummy plug with a projection into the cylinder head so that the piston can be brought gently against it Bring the piston slowly up to the stop by rotating the engine as far as it will go first in a clockwise direction then in an anti clockwise direction Take degree plate readings at each position and calculate th...

Page 45: ...ned through the hole in the cover blanked off with a rubber plug In order to ensure that the clutch springs exert their full pressure on the friction plates the operating mechanism must be adjusted so that there is a slight amount of play between the pin the steel ball and the push rod FIG B24 Clutch adjustment If there is insufficient play between these items the clutch will continually tend to s...

Page 46: ... C1 INDEX Page DESCRIPTION C3 DISMANTLING AND REBUILDING Concentric Float Chamber C3 HINTS AND TIPS C4 INSPECTING THE CARBURETTER COMPONENTS C4 TRACING FAULTS C5 TUNING THE CARBURETTER C7 VARIABLE SETTINGS AND PARTS C6 ...

Page 47: ...D14 4 CARBURETTER C2 FIG C 1 Concentric carburetter exploded ...

Page 48: ...ntrol known as an air slide for use when starting from cold This slide partially blocks the passage of air through the main choke enrichening the mixture DISMANTLING AND REBUILDING Concentric Float Chamber Unscrew the two fixing nuts and withdraw the carburetter from its mounting studs it will not be necessary to detach the cables from the handlebar controls Take out the two Phillips head fixing s...

Page 49: ... needle for similar signs 5 Check the float needle for efficiency by inserting it into the float needle seating block pouring a small amount of petrol gasoline into the aperture surrounding the needle and checking it for leakage 6 Ensure that the float is not punctured by shaking it to see if it contains any fuel Do not attempt to repair a damaged float A new one can be purchased at a small cost 7...

Page 50: ... affected and care must be taken to avoid overheating the engine due to a weak mixture Testing with the air control will indicate if a larger main jet and higher needle position are required Air Control The air control should at all times be kept open except when starting from cold When the engine fires the control must be opened Repeated operation of the kickstart pedal with the air valve closed ...

Page 51: ...with a larger cut away see paragraph E page C7 Position 4 Lower needle one or two grooves see paragraph D page C7 To Cure Weakness Position 1 Fit larger main jet Position 2 Screw pilot air adjusting screw in Position 3 Fit a throttle with a smaller cut away see paragraph E page C9 Position 4 Raise needle one or two grooves see paragraph D page C7 Positions 1 2 3 and 4 refer to positions of throttl...

Page 52: ...nly used for starting the engine and for experimenting with air supply It must be fully open when the engine is running PARAGRAPH G Tickler or Primer This is a small spring loaded plunger in the float chamber wall When pressed down on the float the needle valve is allowed to open and so flooding is achieved Flooding temporarily enrichens the mixture until the level of the fuel subsides to normal T...

Page 53: ...his throttle position and there is no spitting either the jet needle is much too high or a lower throttle cut away is required to cure richness FOURTH Needle with throttle in position 4 Fig C3 The needle controls a wide range of throttle openings and also the acceleration Try the needle in as low a position as possible viz with the clip in a groove as near the top as possible if acceleration is po...

Page 54: ...RAME ALIGNMENT D3 SWINGING ARM Removal D4 Alignment D6 REAR DAMPERS D6 PETROL TANK D7 DUALSEAT D8 SIDECOVERS D8 CHAINGUARD D9 MUDGUARDS D9 AIR CLEANER D9 HEADLAMP REMOVAL D10 CONTROL CABLE REPLACEMENT Throttle Cable D11 Air Control Cable D12 Front Brake Cable D12 Clutch Cable D12 ...

Page 55: ...D14 4 FRAME AND FITTINGS D2 FIG D1 Frame dimensions ...

Page 56: ...D3 shows the basic set up for checking the D14 Bantam frame though variations can be used according to the facilities available Place the blocks into the steering head insert the mandrel and support with the vee blocks at one end to ensure that it is parallel with the surface of the table Insert the swinging arm spindle through its pivot hole in the rear frame member Now using jacks or packing pie...

Page 57: ...rm pivot spindle should be vertical This can be checked using the set square and internal calipers or a slip gauge between the spindle and the square Find the frame tube centre line and make a thorough check at all points to ensure that the frame is not twisted A check must also be taken at the engine mounting lugs Errors at any point should not exceed 1 32 79 mm ...

Page 58: ...e brake light switch at its snap connectors The brake pedal is retained by a pivot bolt with nut and a return spring On Bushman models only the prop stand must also be removed the bracket for which is held by two nuts and bolts Removal of the special bolts at the top of the brackets also releases the ends of the sub frame or saddle support which can be tied up out of the way to provide more access...

Page 59: ...forks are square to the pivot they must be swept up at 90 to the position illustrated so that the pivot is vertical Next find the centre of the pivot and check that all measurable points are in accordance with the dimensions shown in Fig D5 NOTE There may also be variation in the rear dampers and a careful examination should be made of the overall length between the mounting eyes of each unit It i...

Page 60: ... the dampers to the machine note that the top fixing bolts also retain the ends of the dualseat bracket PETROL TANK Turn off the petrol tap and detach the petrol pipe at its union on the float chamber Take out the two fixing bolts from the front of the tank and note that the large washers are fitted between the tank brackets and the steering head lugs Loosen the rear fixing bolt it will not be nec...

Page 61: ...ay twist and break the internal connections To remove the right hand sidecover and back plate on the Supreme models first unscrew the two chrome headed screws in the cover these have a circlip fitted on them behind the cover to prevent them from falling out When the cover is removed unclip the rubber band from around the air cleaner element and remove Behind the element is one of the fixing bolts ...

Page 62: ...wo nuts and bolts hold the guard at the top to the saddle support rail brackets Take off the left hand sidecover and remove the coil held by two nuts and bolts Also take out one nut and bolt fixing the rectifier bracket to the top of the guard Disconnect the rear light cables at their connectors near the battery The brown cable is connected to the brake light switch and the black cable joins the m...

Page 63: ...r bracket to the sub frame clips Pull the adaptor hose from its location in the air cleaner base plate and withdraw the unit The air cleaner can be dismantled by first removing the clip screws which hold the perforated band The element is composed of paper and it is therefore inadvisable to attempt to clean it If it appears contaminated with excessive quantities of dirt replace it with a new unit ...

Page 64: ...wo screws from the twist grip control and take off the top half to expose the cable nipple Ease the nipple out of the grip and remove the cable Fit the replacement cable to the grip by inserting it up through the lower half and locating the nipple in its slot Replace the top half of the grip but before tightening the screws check that the grip turns freely Do not replace the cable stop at this sta...

Page 65: ...d under the fork leg pinch bolt The replacement cable is supplied complete with its toggle and can be fitted in the reverse manner Remember to re adjust the brake cable and test the efficiency of the brake thoroughly before using the machine Clutch Cable The cable must first be detached from the clutch actuating lever situated behind the inner timing cover next to the gearbox sprocket As it will b...

Page 66: ...E2 Oil Seals E3 Rebuilding the Fork Legs E3 Replacing the Fork Legs E4 FRONT FORKS Bushman and Sports Hydraulic Damping E4 Dismantling the Fork Leg E4 Oil Seals E5 Rebuilding the Fork Leg E5 Replacing the Fork Leg E6 FORK ALIGNMENT E6 STEERING HEAD Adjusting Steering Head Races E8 Renewing Steering Head Races E8 ...

Page 67: ...tain the right amount of the correct grade oil see page A3 A holder containing an oil seal is screwed on to the top of the lower sliding member and prevents oil from seeping around the main tube when the forks are compressed REMOVING THE FORK LEGS Before starting work on the forks it is advisable to have the following tools and replacements available 2 off 2 off 2 off 90 5230 90 5229 97 2557 61 33...

Page 68: ...e unscrewed from the top of the restrictor rod and withdrawn The restrictor rod should not have been subjected to any wear but can if necessary be unscrewed from the base of the sliding member The lower bush is a press fit on to the end of the main tube and can be removed by first prising open the joint with a thin bladed instrument then tapping it off with a soft mallet Ensure on replacement that...

Page 69: ...that of the other type with the exception that when the lower member rises oil is forced up around the fork shaft and enters it through a small hole in the fork shaft This hole limits by virtue of its size the quantity of oil that can escape It is this pressure resistance that slows the fork action On recoil the retraction of the main shaft creates a vacuum which sucks the oil back through the hol...

Page 70: ...slid off the shaft OIL SEALS If it is necessary to change the oil seal place the lower edge of the holder on a wooden block and enter service tool No 61 3006 into the top of the holder Give the tool a sharp blow with the hammer and the seal will be driven out To fit a replacement seal coat the outside with a good jointing compound and whilst still wet enter the seal squarely into the holder with t...

Page 71: ... other leg Before refitting the leg to the steering head apply a liberal coating of grease to the spring and place the spring in position in the oil seal holder REPLACING THE FORK LEG Now screw service tool No 61 3350 minus the nut and collar into the top of the tube and pass the tube up through the two yokes fit the collar and nut and draw the tube firmly home into its taper Tighten the pinch bol...

Page 72: ...quipment including such items as knife edge rollers and dial gauges Special gauges are also necessary when checking the yokes It is possible however to make a reasonable check of the tubes by rolling them on a good flat surface such as a piece of plate glass but it is not a simple operation to straighten a bent tube Should the tube be obviously bent but not kinked then it may be possible to carry ...

Page 73: ... so that the front wheel is raised clear of the ground then standing in front of the wheel attempt to push the lower fork legs backwards and forwards Should any play be detected it will be necessary to adjust the steering head races It may not be possible to distinguish between play in the head races and play in the fork leg bushes though in some cases there may be both If possible ask a friend to...

Page 74: ...t cap and prepare to examine the bearings There should be twenty four steel balls in each race see page A3 for details on lubrication The lower cone can be prised off the column but when fitting the replacement care must be taken to see that the cone is seated squarely For this purpose a length of heavy gauge steel tubing long enough to clear the column and 1 in diameter is most useful for driving...

Page 75: ...s F3 Brake Shoes F3 REAR WHEEL Removal F3 Hub Dismantling F4 Fitting New Bearings F4 Brake Shoes F4 Chainwheel F4 BRAKE ADJUSTMENTS F4 REAR CHAIN ADJUSTMENT F5 RENEWING BRAKE LININGS F5 SECURITY BOLTS F6 WHEEL BUILDING F6 WHEEL BALANCING F7 WHEEL ALIGNMENT F7 TYRES Removal F8 Replacement F10 Pressures F12 ...

Page 76: ... Sports model has the same internal details as the other Bantams but the hub is fitted with a full width outer casing FIG F1 Front wheel removal FIG F2 Unscrew the large nut F Fig F2 from the wheel spindle The spindle can be prevented from turning by applying the brake using a short length of steel tubing over the operating lever Take off the cover plate complete with brake shoes cam and fixed ful...

Page 77: ...cap and circlip Do not omit to fit the shim between the dust cap and bearing Sports models only Front Brake Shoes After the brake plate has been removed from the wheel the brake shoes can be released by levering them outwards and upwards off the cam and fulcrum pin The springs are very strong so take care not to trap the fingers behind the shoes NOTE Avoid handling serviceable brake linings with g...

Page 78: ...ng and that the bearing is seated well up to the hub shell abutment and the shoulder on the spindle After fitting the drive side bearing and its retainer insert the spindle from the right hand side and drive in the right hand bearing to the spindle shoulder Fit the distance piece C Fig F4 on to the spindle then the speedometer gearbox taking care to mesh the driving dogs When the brake cover plate...

Page 79: ...rake as described opposite NOTE It is strongly recommended that the wheel alignment is checked after any adjustment to the rear chain has been made full details of this are given on page F7 RENEWING BRAKE LININGS Holding the brake shoe in a vice cut off the peened over portion of the rivet with a good sharp chisel as shown below FIG F5 Drive out the rivets with a suitable pin punch and discard the...

Page 80: ...rom the tube It has been found necessary therefore to fit a security bolt to the rim of each wheel on the Bushman models Before attempting to remove or replace a tyre the security bolts must be completely loosened FIG F8 Security bolt WHEEL BUILDING This is a job which is best left to the specialist as it is essential that the wheel is laced correctly and that when truing the spokes are correctly ...

Page 81: ... only a little at a time as once the spoke is under tension only a fraction of a turn is sometimes sufficient to throw the rim badly out of truth WHEEL BALANCING When a wheel is out of balance it means that there is more weight in one part than in another This is very often due to variation in the tyre and at moderate speeds will not be noticed but at high speeds it can be very serious particularl...

Page 82: ... screwed in or out as necessary after the spindle nuts have been slackened off A machine suffering accidental damage may have wheels so out of alignment that they cannot be corrected in this way Frame fork or wheel geometry may be basically upset in these cases a specialist repairer can probably reset any offending assembly using information in section D TYRE REMOVAL There are a few points about t...

Page 83: ...ne lever and insert further along the tyre continuing every two to three inches until the bead is completely removed see Fig F12 FIG F12 Removing the first bead FIG F13 Take care when inserting levers not to pinch the inner tube as this will result in a puncture Lift the valve out of the rim and remove the tube Stand the wheel upright insert a lever between the remaining bead and the rim and pull ...

Page 84: ...hat are showing through Replace the rim tape with the rough side next to the rim FIG F14 Cover and tube assembled ready for fitting FIG F15 Commencing to fit the tyre Fit the tube in the tyre and inflate just sufficient to round it out without stretch Too mush air makes fitting difficult and too little will make the tube more liable to be nipped by the levers Dust the tube and inside the cover wit...

Page 85: ...at the tube adjacent to the valve is not trapped under the bead then pull the valve back firmly into position Before inflating check that the fitting line on the tyre wall just above the bead on each side is concentric with the rim If necessary bounce the wheel to help seat the tyre but see that there is adequate pressure to prevent damaging the tyre or tube and only use moderate force If the tyre...

Page 86: ...he tyre pressures should be increased as follows Front Tyre Add 1 lb per square inch for every 28 lb in excess of 140 lb Rear Tyre Add 1 lb per square inch for every 14 lb in excess of 140 lb If additional load such as a pillion passenger or luggage is to be carried the actual load bearing upon each tyre should be determined and the inflation pressures increased in accordance with the Dunlop Load ...

Page 87: ...est G6 Premature Bulb Failure G7 Contact Breaker G7 Condenser G7 Ignition Coil G8 Constructing a 1 ohm Load Resistor G8 BUSHMAN PASTORAL MODELS Generator Testing G9 Ignition Feed Coil G9 Premature Bulb Failure G10 Dipper Switch G10 SPARKING PLUG G10 HEADLAMP Description G11 Beam Adjustment G12 TAIL AND STOP LAMP G12 HORN Description G13 Horn Adjustment G13 WIRING DIAGRAM G14 WIRING DIAGRAM Bushman...

Page 88: ...or re installing new cables These connectors are not intended as plugs and sockets for frequent manipulation and should only be used when testing or fault finding It is important that they are making perfect contact as should all other connection points throughout the system BATTERY The battery used on Bantam machines with the exception of the Bushman Pastoral is a Lucas six volt unit type PUZ5E 1...

Page 89: ...s the battery should be cleaned as follows To gain access to the battery first take off the dualseat as detailed on page D8 Remove the battery cover and clean the battery top Examine the terminals if they are corroded scrape them clean and smear them with a film of petroleum jelly or with a silicone grease Remove the vent plugs and check that the vent holes are clear and that the rubber washer fit...

Page 90: ...002 to the observed reading to obtain the true specific gravity at 60 F The temperature must be indicated by a thermometer having its bulb actually immersed in the electrolyte and not the ambient temperature To take a temperature reading tilt the battery sideways and then insert the thermometer EMERGENCY STARTING The alternator equipment provides an emergency starting system which when the ignitio...

Page 91: ...eck between Revolutions per minute Volts output Yellow green Orange green 2 000 3 000 2 000 3 000 4 4 75 7 5 8 5 NOTE During these series of tests the importance of correct battery connections cannot be over emphasised The translucent lead should always be connected to the battery positive terminal and the brown lead to the negative terminal Reversal of these connections will invariably burn out t...

Page 92: ...ead firmly with a second spanner to prevent it from turning If this precaution is not taken the rectifier plates may twist and break the internal connections The cable snap connectors should be clean and tight as poor connections can give rise to rectifier failure owing to over load or arc burning Switches On all models except the Bushman Pastoral both the ignition and lighting switches are mechan...

Page 93: ... unit Check the action of the breaker arm on the pivot as any sticking of this arm can cause intermittent difficulty On no account should the star shaped retaining washer on the breaker arm be removed from the pivot as the amount of end float is strictly controlled and is essential to the correct functioning of the contact breaker Condenser Should the capacity be suspect first check for good conta...

Page 94: ...g it into two equal parts and calibrating it as follows 1 Fix a heavy gauge flexible lead to the folded end of the wire and connect this lead to the positive terminal of a six volt battery 2 Connect a D C voltmeter 0 10 volts across the battery terminals and an ammeter 0 10 amp between the battery negative terminal and the free ends of the wire resistance using a crocodile clip to make the connect...

Page 95: ...uld be a good quality moving coil instrument and the 1 ohm resistance must be accurate otherwise correct results cannot be obtained With respect to column 3 the light should of course be switched on before checking these output figures and care should be taken to see that the correct bulbs are fitted with in the lamps at the time of testing When testing in accordance with column 4 be sure the ligh...

Page 96: ...ve the sparking plug a box spanner 13 16 19 5 mm across flats should be used and if any difficulty is encountered a small amount of penetrating oil should be placed at the base of the sparking plug and time allowed for penetration Examine the plug for signs of petrol gasoline fouling This is indicated by a dry sooty black deposit which is usually caused by over rich carburation although ignition s...

Page 97: ...ring it is advisable to clean the threads of the plug with a wire brush then smear a minute amount of graphite grease on to the threads If the ignition and carburation settings are correct and the plug has been correctly fitted but over heating still occurs then it is possible that carburation is being adversely affected by an air leak between the carburetter and the cylinder This possibility must...

Page 98: ...han 3 feet 6 inches above that plane Of course these instructions may vary with overseas lighting regulations The headlamp must therefore be set so that the main beam is directed straight ahead and parallel with the road when the motor cycle is fully loaded To achieve this place the machine on a level road facing a wall at a distance of 25 feet away With a rider and passenger seated on the machine...

Page 99: ... armature which impacts on the cone face and causes the tone disc of the horn to vibrate The magnetic circuit is made self interrupting contacts which can be adjusted externally If the horn fails to work check the mounting bolts etc and horn connection wiring Check the battery for state of charge A low supply voltage at the horn will adversely affect horn performance If above checks are made and t...

Page 100: ...D14 4 ELECTRICAL SYSTEM G14 FIG G8 Wiring diagram all models except Bushman Pastoral ...

Page 101: ...D14 4 ELECTRICAL SYSTEM G15 FIG G9 Wiring diagram Bushman Pastoral models ...

Page 102: ...D14 4 CHAINS H1 INDEX Page Chain Measurement H2 Chain Alterations and Renewals H2 Chain and Sprocket Inspection H3 ...

Page 103: ... be replaced With a new pitch chain 23 pitches will come to the 11 mark on the rule and a sufficiently accurate check for subsequent wear is to take a limit of 11 for 23 pitches Naturally the test should be made carefully to obtain an accurate result The chain is first washed in kerosene to ensure that all joints are free and laid unlubricated on a flat board If it is anchored at one end by a nail...

Page 104: ...prockets If the latter are in correct alignment the inner plates of the chain will be lightly polished equally on their inner sides and this is not detrimental However if one side shows considerably more wear than the other it indicates that the shafts are not parallel as viewed from the above or not in the same plane as viewed from the back of the machine If the inner plates on both sides of the ...

Page 105: ...6 1 383 1 659 5 530 5 945 2 489 2 765 1 936 2 212 6 913 7 604 7 604 8 295 0 830 1 106 1 936 2 212 Abbreviations A F B S C B S F Across Flats British Standard Cycle British Standard Fine L H T P I W F Left hand Thread Threads Per Inch Whitworth Form CHEMICAL LOCKS The use of Locktite AVV Red is recommended on the clutch centre nut TORQUE WRENCH EXTENSIONS The torque figures listed overleaf indicate...

Page 106: ...YWHEEL STRIPPING BARS 2 K2 CLUTCH SPRING COMPRESSOR K2 SMALL END BEARING EXTRACTOR K2 REAR DAMPER TOOL K3 WHEEL BEARING RETAINER PEG SPANNER K3 ENGINE SPROCKET EXTRACTOR K3 FORK LEG REMOVAL TOOL K4 OIL SEAL EXTRACTOR PUNCH K4 OIL SEAL ASSEMBLY TOOL K4 OIL SEAL HOLDER TOOLS K5 ...

Page 107: ...D14 4 SERVICE TOOLS K2 FIG K1 61 3791 Small end Bearing Extractor FIG K2 61 3206 Flywheel Bolster 61 3209 Flywheel Punch 61 3208 Flywheel Stripping Bars 2 FIG K3 61 3191 Clutch Spring Compressor ...

Page 108: ...D14 4 SERVICE TOOLS K3 FIG F4 61 3644 Wheel Bearing Retainer Peg Spanner FIG K5 61 3796 Engine Sprocket Extractor FIG K6 61 5064 Rear Damper Tool ...

Page 109: ...D14 4 SERVICE TOOLS K4 FRONT FORKS FIG K7 61 3824 Fork leg removal tool FIG K8 Oil seal extractor punch No 61 3006 FIG K9 Oil seal assembly tool No 61 3007 ...

Page 110: ...D14 4 SERVICE TOOLS K5 FIG K10 61 3633 Fork Leg Oil Seal Holder Tool FIG K11 Oil seal holder fitting and removal tool No 61 3005 ...

Page 111: ...ND WIRE GAUGES L5 B S F AND B S W SCREW THREADS L6 B S C SCREW THREADS L7 UNIFIED SCREW THREADS L8 B A SCREW THREADS L9 MILES PER GALLON TO LITRES PER 100 KILOMETRES L9 GALLONS TO LITRES L9 PINTS TO LITRES L10 POUNDS PER SQUARE INCH TO KILOGRAMS PER SQUARE CENTIMETRE L10 FOOT POUNDS TO KILOGRAMETRES L10 MILES TO KILOMETRES L10 POUNDS TO KILOGRAMS L10 ...

Page 112: ...77 8 431 8 685 8 939 8 1193 8 8 203 2 457 2 711 2 965 2 1219 2 9 228 6 482 6 736 6 990 6 1244 6 ONE INCH 25 399978 millimetres ONE METRE 39 370113 inches ONE MILE 1 6093 kilos ONE KILO 62138 miles DECIMALS TO MILLIMETRES FRACTIONS 1 1000 1 100 1 10 Inches Mm Inches Mm Inches Mm 001 0254 01 254 1 2 54 002 0508 02 508 2 5 08 003 0762 03 762 3 7 62 004 1016 04 1 016 4 10 16 005 1270 05 1 270 5 12 70 ...

Page 113: ...13 64 203125 5 1594 45 64 708125 17 8594 7 32 21875 5 5562 23 32 71875 18 2562 15 64 234375 5 9531 47 64 734375 18 6531 1 4 25 6 3500 3 4 75 19 0500 17 64 265625 6 7469 49 64 765625 19 4469 9 32 28125 7 1437 25 32 78125 19 8437 19 64 296875 7 5406 51 64 796875 20 2406 5 16 3125 7 9375 13 16 8125 20 6375 21 64 328125 8 3344 53 64 828125 21 0344 11 32 34375 8 7312 27 32 84375 21 4312 23 64 359375 9 ...

Page 114: ... 58268 2 2 04725 2 44095 2 83465 3 22835 3 62205 3 2 08662 2 48032 2 87402 3 26772 3 66142 4 2 12599 2 51969 2 91339 3 30709 3 70079 5 2 16536 2 55906 2 95276 3 34646 3 74016 6 2 20437 2 59843 2 99213 3 38583 3 77953 7 2 24410 2 63780 3 03150 3 42520 3 81890 8 2 28347 2 67717 3 07087 3 46457 3 85827 9 2 32284 2 71654 3 11024 3 50394 3 89764 MILLIMETRES TO INCHES FRACTIONS 1 1000 1 1000 1 1000 MM I...

Page 115: ...2 0635 WIRE GAUGES NO OF GAUGE IMPERIAL STANDARD WIRE GAUGE BROWN SHARPE S AMERICAN WIRE GAUGE INCHES MILLIMETRES INCHES MILLIMETRES 0000 000 00 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 400 372 348 324 300 276 252 232 212 192 176 160 144 128 116 104 092 080 072 064 056 048 040 036 032 028 024 022 020 018 0164 0148 0136 0124 10 160 9 448 8 839 8 299 7 620 7...

Page 116: ...626 1 0559 1 0539 1 0472 1 664 1 98 995 1 1 4 9 1 1 8 1 1077 9637 1 1876 1 1809 1 1789 1 1722 1 852 2 15 1 115 1 3 8 8 1 15 64 1 2149 1593 1 3041 1 2970 1 2950 1 2879 2 042 2 37 1 240 1 1 2 8 1 358 1 3399 4100 1 4291 1 4220 1 4200 1 4129 2 210 2 56 1 365 1 5 8 8 1 31 64 1 4649 1 6854 1 5541 1 5470 1 5450 1 5379 2 400 2 78 1 400 B S W SCREW THREADS PITCH DIAMETER HEX NUT BOLT FLATS CORNERS DIA OF B...

Page 117: ...846 0 0205 0 2813 0 2608 0 2403 5 16 26 0 03846 0 0205 0 3125 0 2920 0 2715 3 8 26 0 03846 0 0205 0 3750 0 3545 0 3340 26 0 03846 0 0205 0 4375 0 4170 0 3965 7 16 20 0 05000 0 0266 0 4375 0 4109 0 3843 26 0 03846 0 0205 0 5000 0 4795 0 4590 1 2 20 0 05000 0 0266 0 5000 0 4734 0 4468 26 0 03846 0 0205 0 5625 0 5420 0 5215 9 16 20 0 05000 0 0266 0 5625 0 5359 0 5093 26 0 03846 0 0205 0 6250 0 6045 0...

Page 118: ...49 0 3194 7 16 20 0 0305 0 4321 0 4016 0 3710 20 0 0305 0 4946 0 4641 0 4334 9 16 18 0 0341 0 5568 0 5227 0 4886 5 8 18 0 0341 0 6193 0 5852 0 5511 1 28 0 0219 0 9955 0 9736 0 9517 1 28 0 0251 1 250 1 2202 1 2144 COARSE UN C 20 0 0304 0 2448 0 2145 0 1839 5 16 18 0 0338 0 3070 0 2722 0 2391 3 8 16 0 0382 0 3690 0 3309 0 2925 13 0 0471 0 4930 0 4460 0 3988 9 16 12 0 0535 0 5625 0 5064 0 4554 7 8 16...

Page 119: ... 23 24 24 14 12 13 78 13 45 13 14 12 84 12 55 12 28 12 02 11 77 11 53 25 25 26 26 27 27 28 28 29 29 11 30 11 08 10 87 10 66 10 46 10 27 10 09 9 91 9 74 9 58 30 30 31 31 32 32 33 33 34 34 9 42 9 26 9 11 8 97 8 83 8 69 8 56 8 43 8 31 8 19 35 35 36 36 37 37 38 38 39 39 8 07 6 89 7 85 7 74 7 63 7 53 7 43 7 34 7 24 7 15 40 41 42 43 44 45 46 47 48 49 7 06 6 89 6 73 6 57 6 42 6 28 6 14 6 01 5 89 5 77 50 ...

Page 120: ...028 13 411 1 106 2 489 3 871 5 254 6 636 8 019 9 401 10 784 12 166 13 549 1 244 2 627 4 009 5 392 6 774 8 157 9 540 10 922 12 305 13 687 10 20 30 40 50 60 70 80 90 MILES TO KILOMETRES 0 1 2 3 4 5 6 7 8 9 10 20 30 40 50 60 70 80 90 16 093 32 187 48 280 64 374 80 467 96 561 112 654 128 748 144 841 1 609 17 703 33 796 49 890 65 983 82 077 98 170 114 264 130 357 146 451 3 219 19 312 35 406 51 499 67 5...

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