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To rub dry and caked mud from the frame, tank and mudguards means that the

enamel on these parts will be subjected to an abrasive action which will quickly

destroy the polish.  Soak the mud first, and then float it off with copious supplies of

clean water supplied either with a hose or a sponge.  If a hose is used, take care not to

direct the stream of water directly on to the hub bearings, magneto and carburetter.

When all dirt is removed, dry and polish off with a clean duster.
The engine and gearbox are best cleaned with a brush and paraffin, and then

dried off with a clean rag.

ENGINE

Lubrication

Lubrication for the engine is provided by oil dissolved in the petrol to provide a

moisture commonly called “petroil”.  The filler cap on top of the petrol tank will be

found to incorporate a tubular extension which projects into the tank.  This serves as

a measure for lubricating oil and is used for preparing the correct mixture of petrol

and oil required.  The correct proportion of oil to petrol is given on page 18, and the

grades of oil recommended should be used as lighter grades may prove unsuitable.

For correct running of the engine and also for adequate lubrication, it is essential

that the oil should be completely dissolved in the petrol, and it is, therefore,

preferable to mix the two in a separate container before pouring into the tank.  If this

is not possible, however, as for instance, when obtaining petrol from a wayside pump,

the oil should be put into the petrol after filling up with the latter and the machine

should be shaken thoroughly to ensure correct mixing of the two liquids.  If this is not

done, there is a risk of liquid oil undiluted with petrol reaching the carburetter and

clogging the fuel supply system.  As the only lubrication for the engine is by means

of fuel drawn in through the carburetter the machine must not be coasted downhill for

long periods with the throttle shut as the engine may suffer seizure through lack of

lubrication.

Ignition Timing

The ignition timing is accurately set within very close limits and there is no manual

adjustment for the rider as this has been found quite unnecessary in practice. 

 

The

contact breaker cam (A) Fig. 2, is keyed on to an extension of the mainshaft, and its

position with reference to the piston position is therefore constant.

Any variation in timing can only be secured by moving the contact breaker

housing (B)

 

Fig. 2, or the rocker arm (C).  The former can be rotated through a very

small angle by releasing the screws (D), not forgetting to retighten them after the

adjustment has been made.  It is emphasised that this is a works adjustment rather

than one which the private owner is ever likely to carry out.

In order to obtain correct timing and proper functioning of the contact breaker,

the points must be set when in the fully open position to the correct gap, and this

point should be checked periodically as recommended on page 28.  To do this, turn

the engine until the points are fully open and insert a feeler gauge between them.  The

correct gap in this position should be .015 in. (.38 mm.) and if this is found to be

wrong release screw (E) about one turn with a screwdriver and move the adjusting

plate up or down until the correct gap of .015 in. has been restored, finally

retightening screw (E).

10

www.ClassicCycles.org

Содержание D1 125 c.c. Bantam

Страница 1: ...00 4036 Instruction Manual Models D1 125 c c Bantam D3 150 c c Bantam Major D5 150 c c Bantam Major...

Страница 2: ...major overhauls but if any owner feels he is competent to carry out this type of work a service manual and an illustrated priced spares catalogue for this machine can be obtained from his B S A spare...

Страница 3: ...FIG 1 The Controls 3...

Страница 4: ...ARBOX HUBS IGNITION TIMING LUBRICATION CHART LUBRICATION SYSTEM ROUTINE MAINTENANCE REAR SUSPENSION RUNNING IN SPARKING PLUG STEERING HEAD TECHNICAL DATA TRANSMISSION WHEEL REMOVAL FRONT WHEEL REMOVAL...

Страница 5: ...Gear ratios top second first Clutch friction plates Chain size and pitch front 250 in rear 335 in Teeth on engine sprocket gearbox sprocket clutch sprocket rear chainwheel 7 0 11 7 22 0 3 50 117 17 1...

Страница 6: ...ght handlebar it controls the throttle opening To open the throttle i e to increase the engine speed turn the grip so that the top moves towards the rider Full movement is about a quarter of a turn Fr...

Страница 7: ...the bottom fork yoke To operate the lock turn the forks to the left then turn the key in the lock to release the plunger This prevents the machine being driven or wheeled DRIVING To Start the Engine...

Страница 8: ...pply them smoothly and progressively Try to anticipate the need to change gear or to brake so that your riding is not jerky or untidy Maintain a natural riding position as this provides maximum contro...

Страница 9: ...tion will serve as a guide to the periods between servicing and the method of carrying out the various adjustments will be found under the appropriate headings in the later chapters Weekly Check tyre...

Страница 10: ...roughly to ensure correct mixing of the two liquids If this is not done there is a risk of liquid oil undiluted with petrol reaching the carburetter and clogging the fuel supply system As the only lub...

Страница 11: ...e running of the engine Ignition timing model D5 Piston position of this model is 1 16 in before top dead centre FIG 2 Contact Breaker DECARBONISATION Decarbonising is extremely simple and should be c...

Страница 12: ...lts are unscrewed so that the tank can be raised slightly Take care when removing the barrel to support the piston as it emerges from the end of the bore in order that it may not be damaged as it fall...

Страница 13: ...t first putting a smear of oil on the gudgeon pin not forgetting a new circlip to replace the one which was removed THE PISTON MUST BE REPLACED IN ITS ORIGINAL POSITION I E WITH PISTON RING GAPS TOWAR...

Страница 14: ...less it becomes absolutely necessary Reassembly Before attempting to replace the cylinder barrel over the piston smear the latter generously with engine oil and then place it over the piston carefully...

Страница 15: ...The sparking plug Remove the sparking plug every 1 000 miles 1 500 Km or so for inspection If the carburation system is in correct adjustment the sparking plug points should remain clean almost indef...

Страница 16: ...ig 5 NEVER ATTEMPT TO MOVE THE CENTRE ELECTRODE and it is always advisable to use the special plug gap tool illustrated obtainable at 2 from any Champion Plug stockist or from the Champion Sparking Pl...

Страница 17: ...nkcase and when this occurs starting is quite impossible until it is drained away by the removal of the crankcase drain plug which is the smaller of the two plugs under the crankcase Air Cleaner This...

Страница 18: ...half filler cap measures to each gallon of petrol OIL BRAND ENGINE GEARBOX GREASE POINTS WAKEFIELD Castrol Two Stroke Oil 1 16 Or Castrol XXL Castrol XXL Castrolease Heavy SHELL 2T Petroiler Mix or 2T...

Страница 19: ...eering head Fork legs Clutch operation Speedometer drive Rear suspension units plunger Contact breaker cam pad 9 9 9 9 9 9 9 A FEW DROPS OF ENGINE OIL NO PART PAGES 10 11 12 13 14 Saddle nose bolt exc...

Страница 20: ...utch adjustment will be found at the left hand end of the gearbox mainshaft see Fig 8 and it consists of an adjusting pin C screwed into the clutch withdrawal quick thread sleeve and a locknut B to se...

Страница 21: ...rew it half a turn and holding it in this position retighten the locknut If the adjustment is correctly made in this manner it will be found that there is a small amount of free play at the clutch lev...

Страница 22: ...evel of dipstick WHEELS Hub Lubrication Inject grease through the nipples in the centres of the hubs Do not over lubricate or grease may be forced onto the brake linings and cause ineffective brakes T...

Страница 23: ...rame models and in for swinging arm frame models Make sure that the wheel is hard up against the adjusters when checking and also that the adjustment is equal on both sides of the wheel so that the la...

Страница 24: ...will stand below the lining surface this is important since the rivets will otherwise score the brake drum Insert the rivets into the holes and rivet them over on the inside of the shoe This is easily...

Страница 25: ...lb horn unscrew this item and lift off the steering head dust cover On other machines the dust cover is held in position by a central screw FIG 10 Front fork and steering head D1 Model only Slacken th...

Страница 26: ...e pinch bolts A and B FIG 11 Rear suspension unit D1 The central columns of the suspension units can then be tapped out from underneath and withdrawn through the top lugs When this is done the remaind...

Страница 27: ...function of the alternator and rectifier to maintain the battery in a charged state for all load conditions This is accomplished by a system of coil switching which adjusts the generator output accor...

Страница 28: ...ich previously went to the battery must be insulated and the stop light must be disconnected If this is not done the rectifier may be seriously damaged The machine must only be run without a battery i...

Страница 29: ...on to the exposed thread AS FAR AS IT WILL GO Finally turn the central extractor bolt with a suitable spanner until the flywheel is drawn from its taper Electric Horn The horn is adjusted at the Work...

Страница 30: ...A single bulb is used with direct lighting sets plus two screw in stop light bulbs with battery sets The transparent red plastic portion of the lamp can be removed by unscrewing the two countersunk s...

Страница 31: ...F IG 13 Wiring diagram direct lighting 31...

Страница 32: ...F IG 14 Wiring diagram battery lighting 32 www ClassicCycles org...

Страница 33: ...PARTS ACCESSORIES Click on links below OEM parts online schematics EU OEM parts online schematics US Shop Revzilla for the latest in Motorcycle Accessories Save Up to 45 on Motorcycle Tires J P Cycle...

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