background image

49 

 

 

 

6. REMOVING THE CYLINDER HEAD AND BARREL 

 
Disconnect the fuel pipe (from the carburetter to the fuel tank) and remove the 
Dual Seat and the fuel tank (for dismantling instructions refer to para 13 & 14). 
Disconnect the Ignition coil and sparking plug leads and remove the H. T. Ignition 
coil.  Disconnect  the  exhaust  pipe,  unscrew  the  four  nuts  holding  the  cylinder 
head  to  the  cylinder  barrel  and  remove  the  cylinder  head.  By  means  of  the 
kickstarter bring the pistons into the B.D.C, position and push the cylinder barrel 
upwards. 
 

Note:

 If it is difficult to remove the cylinder head lever it carefully by placing a 

screwdriver between the cylinder head and cylinder fin at the spot where the fins 
join. After dismantling cover up the crankcase opening to prevent dirt entering, 

 

 

 

           

                  

 

     Fig. 30 Disconnecting the exhaust pipes                  Fig. 31 Removing the cylinder head 

 

 

 

 

Содержание B

Страница 1: ...n and Operator s Manual WITH SPECIAL REFERENCE TO SERVICING AND ROUTINE MAINTENANCE OF MOTORCYCLES YEZDI 250 cc MODEL B JAWA 250 cc MODEL 353 04 Manufacturers IDEAL JAWA INDIA PRIVATE LTD MYSORE 570 0...

Страница 2: ...2...

Страница 3: ...3...

Страница 4: ...4...

Страница 5: ...ont wheel 43 2 Removing the rear wheel 44 3 Removing the chaincase and the chain 45 4 Removing the rear chainwheel 45 5 Replacing the wheel ball bearings 45 6 Removing the cylinder head and barrel 49...

Страница 6: ...33 Fitting the piston rings 10 Lubrication chart L H side 34 Front fork sectional view 11 Lubrication chart R H side 35 Lubricating the steering head bearing balls 12 Draining the gearbox oil 36 Lubr...

Страница 7: ...pindle maximum load 214 kg Primary drive of 3 8 x 3 8 in chain 60 links Final driver by 1 2 x 5 16 in chain 120 links Primary and final drive ratios Primary 45 22 T Final 46 19 T Bottom gear 24 12 x 1...

Страница 8: ...8 Fig 2 Engine 250 c c sectional view...

Страница 9: ...9 Fig 3 Plan of the Motorcycle...

Страница 10: ...d lever fitted on L H side of the handlebars The gearbox is of the four speed type forming with the crankcase a monoblock engine unit The gear shifting is foot operated by means of a lever located on...

Страница 11: ...detachable the spindles being of the push out type The number of spokes is 36 in each wheel the spoke dia being 3 5 mm thread M4 The brakes are of full width hub and very efficient The fins along the...

Страница 12: ...sion The rear suspension operates on a circular path The pivoted rear fork is sprung by two cylindrical coil springs and fitted with hydraulic dampers The suspension dampers are protected by chromium...

Страница 13: ...stator Its position on the stator is located by the manufacturers by means of an Oscillograph to ensure most suitable tension for ignition and lighting and this position should never be altered under...

Страница 14: ...o base plate 15 For ignition connected to terminal No 15 of H T Ignition coil 21 For battery charging connected to terminal No 21 of the rectifier 30 Connected to negative terminal of battery 30 Two l...

Страница 15: ...other circuits are cut POSITION 3 Highway night riding Key fully inserted Ignition and charging circuits connoted the pilot light and Tait lamp are on The Head lamp main bulb is supplied with current...

Страница 16: ...16...

Страница 17: ...o the frame underneath the fuel tank The condenser of value 0 2 mF is placed on the frame in the vicinity of the ignition coil The condensor lead is connected to terminal No 1 of the ignition coil The...

Страница 18: ...pointed out that the riding comfort on this type of motorcycle depends above all on the proper operation of the hydraulic dampers A new motorcycle just as a new motor car requires careful running if...

Страница 19: ...0 km p h 37 m p h 75 km p h 47 m p h not limited 4th notch from top 3rd notch from top 3rd notch from top turn turn turn Note During the running 1n period the carburetters are set for a rather rich mi...

Страница 20: ...ning it anticlockwise Keep filler cap breathing hole clean After running in the motorcycle mix oil with fuel at a ratio of 1 to 20 at a ratio 1 to16 during the running in period Fig 7 Oil filling and...

Страница 21: ...retter air intake by turning the air cleaner strangler and flood the carburetter by pressing down the tickler pin Flooding and air intake closing should be carried out only if the engine is cold e ins...

Страница 22: ...gear with your left foot by pushing the foot gear change lever upwards and release the clutch lever slowly while at the same time gradually opening the throttle Should the clutch cable be broken the m...

Страница 23: ...ver into bottom gear and keep the clutch lever depressed When braking also use the front brake but a little later than the rear brake and only when travelling straight on Having finished riding turn o...

Страница 24: ...e carburetter headlamp and brakes clear of water Wipe dry enamelled and chromium plated parts and polish them with flannel or chamois leather The enamelled parts can be polished with an enamel polish...

Страница 25: ...il after every 3 500 km 2 000 miles Change the oil preferably after having finished a trip while both the engine and oil are warm The warm oil will scavenge any accumulated sludge The correct oil leve...

Страница 26: ...he oil rinse both the fork legs thoroughly with petrol make the suspension play several times drain the petrol and let it dry Having screwed in the drainplug 14 fill both fork legs with 175 c c of dam...

Страница 27: ...6 15 2 1 Mobil Grease M P Heavy Grease Retinax A Wheel Bearing Grease Remove wheels clean repack bearings and refit 5000 Secondary Chain 10 1 Mobil Grease M P Graphite Grease Retinax A Multi Purpose...

Страница 28: ...0 miles remove the R H side crankcase cover and with a few drops of oil lubricate the contact breaker arm pin Care has to be taken to ensure that no oil gets on to the contact breaker points The felt...

Страница 29: ...29 Fig 13 Removing the chain connecting link Fig 14 Adjusting the brake...

Страница 30: ...on the inner tube air pressure in relation to the load carried As a rule the tyre has to be inflated so as to keep its original shape even under full load Running on under inflated tyres will result...

Страница 31: ...to the valve Using the tyre levers slip the cover edge over the rim edge Take care not to pinch the tube and thus damage it Having slipped all the cover circumference over the rim edge press the valve...

Страница 32: ...ver gradually on both sides towards the valve Proceed carefully in order not to damage the tube by pinching it between the cover and rim edges Tyre patching is an emergency remedy only during a trip w...

Страница 33: ...tightening these nuts so as to avoid damaging their threads Having adjusted the chain tension retighten the tensioning locknuts properly then the sleeve nut and finally the spindle securing nut Make...

Страница 34: ...e accurately from time to time in the following manner a Screw the hand clutch adjusting screw on the handlebars slightly thus releasing the clutch lever b Clean with petrol or paraffin any dirt from...

Страница 35: ...matic clutch roller 5 Clutch control carrier 10 Automatic clutch cam 11 Cup 7 CARBURETTER The carburetter has been correctly set in the works The jet and the throttle valve have been selected by trail...

Страница 36: ...idling speed of the engine with fully closed throttle can be adjusted by extending or shortening of the throttle cable and by securing the throttle valve by not letting it down to its bottom limit wi...

Страница 37: ...will prevent fine dust particles from passing through the filter and working its way into the engine and causing damage to the vital working parts Running on dusty roads makes more frequent cleaning...

Страница 38: ...MAINTENANCE OF ELECTRICAL EQUIPMENT Examine the leads from time to time and wind insulating tape round insulation cracks Damaged insulating can cause short circuits possibly entailing serious damage...

Страница 39: ...km 120 miles and if necessary adjust the contact breaker point gap and ignition advance See para Ignition timing Fig 22 Removing the fuse Setting the Ignition Timing a Remove the sparking plug from cy...

Страница 40: ...making the gap larger or to the right making the gap smaller g After setting re tighten the stator bolts Warning The contact breaker base plate should never be slackened or rotated in order to set th...

Страница 41: ...ted by tipping the reflector by means of the adjusting button in the top portion of the head lamp rim After releasing loosening the button push it forwards backwards as long as the headlamp beam is re...

Страница 42: ...m piston ring grooves preferably with an old broken piston ring When replacing the piston rings fit the rings into the same grooves in which they were before being removed Having scraped off the carbo...

Страница 43: ...wheel When assembling after pushing home the spindle putting the spring washer into position it must not be forgotten and having placed the lock nut depress and release the front fork several times On...

Страница 44: ...to the right hand side Remove the brake reaction bracket on the L H side slide the wheel off the rubber blocks coupling of the chain wheel and inclining the motorcycle to one side remove the wheel To...

Страница 45: ...ase Using the wire pull the other end of the chain through the rubber guide in the chaincase top half placed in position Slip the top end of the chain over the rear chainwheel and connect the two chai...

Страница 46: ...gs the hub cover of the splined driver should be removed first Press in the new bearings by applying pressure to the outer bearing race using a piece of tube When replacing the rear chainwheel bearing...

Страница 47: ...47 Fig 28 Rear wheel sectional view...

Страница 48: ...48 Fig 29 Front wheel sectional view...

Страница 49: ...w the four nuts holding the cylinder head to the cylinder barrel and remove the cylinder head By means of the kickstarter bring the pistons into the B D C position and push the cylinder barrel upwards...

Страница 50: ...rips Insert one strip under the piston ring in the middle and the two others under the piston ring ends To replace the piston rings proceed in the same manner 8 REMOVING THE CARBURETER a Disconnect th...

Страница 51: ...clutch has five plates with cork inserts and four metal plates plus one pressure plate When reassembling insert first the plate with a cork insert which was under the pressure plate 10 DISMANTLING THE...

Страница 52: ...52...

Страница 53: ...41 and unscrewing the plug screws 32 Remove now the fork head lug and the bottom nacelle can be pushed out II DISMANTLING THE STEERING HEAD AND FORK LEGS Remove first the top nacelle handlebars unscr...

Страница 54: ...the fork legs and the steering head column To remove the front suspension dampers from fork legs unscrew the drain plug 14 Ref Fig 34 and top nut 1 after removal of top nacelle and pull out the entire...

Страница 55: ...r as well as an auxiliary tool box are located 15 REMOVING THE FUEL TANK Disconnect the fuel pipe and unscrew two screws M 8 x 10 securing the front clamp ears and the through bolt with nut 14 12 secu...

Страница 56: ...t from its brackets in the frame and pivoted rear fork As compared to the former the new type damper has increased damping efficiency and is so designed that no topping up with oil is required It is r...

Страница 57: ...o be carried out Remove the cowls para 15 the suspension dampers para 16 The rear wheel pars 2 chaincase para 3 and the rear chain para 4 and exhaust silencers After removing these parts unscrew the b...

Страница 58: ...he nut 10 and pushing the washer off the earthing screw Pull down the securing strap and remove the battery Fig 41 Removing the battery 19 DISMANTLING THE SWITCH BOX Dismantle the switch box only if a...

Страница 59: ...gnition setting is required Unscrew the two screws and remove the cover Before fitting the cover clean the seating faces off mud Tighten the securing screws evenly and check the cover front part to se...

Страница 60: ...nt fuel supply Temporary short circuiting caused by faulty plug lead Weak mixture Improperly mixed petroil Clean the carburetter Open reserve supply tap pass fuel over re fuel inspect inlet manifolds...

Страница 61: ...ncers Insufficient fuel feed Improperly set ignition Improper carburetter setting improper mixture Exhaust silencers clogged Worn cylinder interior and piston Engine drags wrong air crankcase halves o...

Страница 62: ...nts Plug points gap too wide Remove and clean sparking plug Replace plug Clean sparking plug Adjust sparking plug gap to 0 45 mm 0 018 in No spark at lead end Ignition key not inserted Insert the key...

Страница 63: ...carburetter to in the interior of the crankcase 2 PISTON MOVES DOWNWARDS After ignition of the mixture the actual working stroke of the piston begins transmitting the power of the expanding gases by m...

Страница 64: ...64 Fig 42 Two stroke engine operation diagram...

Страница 65: ...65 Printed by PRINTOKRAFT Bombay 400 057 at The Book Centre Ltd Sion East Bombay 400 0022 20000 7 77...

Отзывы: