N-Zeta 501/01 Workshop Manual - page 38

Manual is about: Cezeta and N-Zeta models

Summary of 501/01

  • Page 1

    Orkshop anual this manual covers all cezeta and n-zeta models m w.

  • Page 2

    - 1 - introduction ..................................................................................................... - 4 - carburettor cleaning and maintenance ............................................. - 5 - jikov 2924 m 13 carburettor ...........................................................

  • Page 3

    - 2 - to dismantle the gearbox and crankshaft mechanism ................................................................... - 27 - dismantling the crankshaft assembly .................................................................................................. - 28 - connecting rod for the 501 ...

  • Page 4

    - 3 - pal 02-9421.04 regulator with contactor – technical data and setting ..................................... - 48 - regulator with contactor - mechanical checking .......................................................................... - 49 - operation checking ...................................

  • Page 5: Introduction

    - 4 - n z e t a s c o o t e r r e p a i r m a n u a l introduction this book represents the repair manual for owners of nzeta scooters made by the world famous cz motorcycle works in strakonice czechoslovakia then assembled and finished by jawa new zealand. The reliability of this machine is well kn...

  • Page 6

    - 5 - carburettor cleaning and maintenance on most occasions, carburettor faults are due to impurities entering with the petrol or air. The time for regular carburettor cleaning will depend on the manner in which the machine is used. It is not recommended to carry out any carburettor repairs apart f...

  • Page 7

    - 6 - all these jobs are done without removing the carburettor from the crankcase, the carburettor being accessible after opening the side door. The main jet is also accessible through the side door. To clean it, fine horse hair should be employed and not a piece of wire or any other hard object. Re...

  • Page 8

    - 7 - the idling jet #17, the pilot, air screw #18 and the throttle valve stop screw #15 are located on the r. H. Side of the carburettor and are accessible through the bodywork side door. When repairing the float, push out the float spindle #31a first thus freeing the float #31. Repair the float or...

  • Page 9

    - 8 - the carburettor is set in the works for running in, and it has to be reset after the first 2000 km / 1200miles to the following values: main jet 100 to 102 to solex idling jet 55 to solex needle position 3 rd notch from the top pilot air screw slacken by ¾ of a turn from tight /anticlockwise/ ...

  • Page 10

    - 9 - jikov 2924 s 11 carburettor for the 501/03 to /05 models; jikov 2924 s 13 carburettor for the 502/00 to /01 model fig.2 these are monoblock type carburettors. They are also equipped with a choke device for making the mixture rich to assist in starting the engine when cold. The main jet #24 is ...

  • Page 11

    - 10 - to set the carburettor according to the manufacturers specifications, proceed as follows: first check the throttle valve #4 needle position. Slacken the lock nut #8; screw the cable guide #9 into the mixing chamber top #7 thus freeing the throttle valve #3. After unscrewing the jet carrier #2...

  • Page 12

    - 11 - fig. 2.

  • Page 13

    - 12 - induction silencer maintenance and cleaning for the 501/01 – 03 – 05 models fig. 3 the silencer serves to reduce the engine noise level and replaces the normal air cleaner at the carburettor. For its correct operation, it must be maintained as follows: after about 3000 – 5000 km / 2000 – 3000...

  • Page 14: E N G I N E

    - 13 - e n g i n e the following jobs can be carried out without removing the engine from the bodywork: removal of the cylinder barrel and head for replacement, re-boring or decoking, cleaning or replacement of the piston, replacement of the connecting rod small end bush, ignition advance setting, r...

  • Page 15

    - 14 - to dismantle the cylinder barrel, it is necessary to first unscrew the studs fastening the cylinder barrel to the crankcase. Thread two nuts onto the studs and tighten them onto each other. Now unscrew them together with the stud by turning the bottom nut. In this manner, remove all four stud...

  • Page 16

    - 15 - piston grading according to diameter d2 – model 502 fig.6 a – 0.01 b – 0.01 c – 0.01 nº. Standard 57.860 57.870 57.880 450-12-026 1 st rebore 58.110 58.120 58.130 450-12-027 2 nd rebore 58.360 58.370 58.380 450-12-028 3 rd rebore 58.610 58.620 58.630 450-12-029 4 th rebore 58.860 58.870 58.88...

  • Page 17

    - 16 - cylinder for model 501 scooters, only cylinders with increased bore by 0.01mm as compared to the motorcycle engines have to be employed. Cylinder bores for the individual gradings are indicated in this table; the cylinder barrels are marked on the top flange beside the letter a, b, c determin...

  • Page 18

    - 17 - gudgeon pin bush for models 501/01, 03, 05 gudgeon pin bush diameter is 15.025 0.01mm for standard gudgeon pin grading = dia. 15.000 – 0.0025mm, grading = dia. 14.9975 – 0.0025mm and 15.125 – 0.01mm for oversize gudgeon pin dia. 15.1 – 0.004mm. For models 502/01, 00 gudgeon pin bush diameter ...

  • Page 19

    - 18 - fitting the cylinder barrel and cylinder head clean the crankcase seating face and preferably a new gasket under the cylinder barrel. Provide the cylinder barrel with a coating of clean oil inside, move the piston to tdc by means of the kick starter pedal and then fit the barrel. When fitting...

  • Page 20

    - 19 - fig. 7.

  • Page 21

    - 20 - after removing the fan assembly from the bodywork, remove the rubber cover #5 from the rotor hub. Free the circlip #9 and pull the fan rotor #4 together with the bearings #6, 7 off the fan body shaft #3 using a universal puller or s-37 with extension s-48. Using a suitable bar Ø14mm inserted ...

  • Page 22

    - 21 - the fan required very little maintenance. After approximately 10,000 km / 6,000 miles, remove the fan rotor from its shaft, clean away any old grease from the space between the bearings and apply a small amount of motor grease to the space. It is necessary to check the vee-belt from time to t...

  • Page 23

    - 22 - after pushing out the carbon brushes, take the dynastarter out of the crankcase. Slacken the cam bolt #1 and tap the cam lightly from side to side taking care not to mark it and remove it from the shaft. Screw puller s-49 or a long m10 bolt /one can be obtained from under the luggage compartm...

  • Page 24

    - 23 - gearbox sprocket shaft the clutch operating rod. The bracket should be dismantled further only when some of the bracket parts are worn. Removal of the gearbox sprocket - is the same for both models. After removing the rh crankcase side cover and the clutch operating bracket, straighten the ta...

  • Page 25

    - 24 - remove the recessed pins on the clutch pins compressing the clutch springs wither with the special tool s-9, or with a screwdriver fig. 12 or possibly with a flat spanner. Push the pin out of the opening and remove the spring from the can. Remove the clutch pressure plate and all the clutch p...

  • Page 26

    - 25 - to remove the kick starter quadrant. Remove the kick starter quadrant together with the return spring from the gear change shaft. Take care of the return spring when taking the parts off. Further remove the spacer which is on the gear change shaft. To assemble, proceed in the reverse manner. ...

  • Page 27

    - 26 - to replace the crankshaft and gearbox output shaft seals when replacing the seals on the crankshaft rh end, it is necessary to first remove the dynastarter as described in the paragraph dealing with its removal. Next remove the three screws securing the seal holder and remove the holder and s...

  • Page 28

    - 27 - to dismantle the gearbox and crankshaft mechanism to separate the crankcase halves, dismantle the gearbox and crankshaft assembly are very exacting jobs which should be done under the supervision of an experienced motorcyclist, or entrusted to a service repair shop; this is preferable as the ...

  • Page 29

    - 28 - if the driving gear with hub or the seal are not to be replaced, the gearbox sprocket need not to be removed before separating the crankcase halves. Remove the gear change shaft, the selector fork guide rod and the gears with shafts. Slacken the four screws holding the cam plate to the lh cra...

  • Page 30

    - 29 - checking method before pressing together the crankshaft assembly and of the pressed together components. The crank pin with the crank web has to be checked on the measuring table between two centres by means of the indicating dial fig.18. Lateral run-out - deflection from the perpendicular ma...

  • Page 31

    - 30 - corresponding grading of the connecting rod and crank pin roller grading marked a b c d e f g h i j k l m n o connecting rod crank pin 6 6 6 4 2 12 12 12 10 8 18 18 18 16 14 v iii i i i v iii i i i v iii i i i connecting rod crank pin 5 5 3 1 11 11 9 7 17 17 15 13 iv ii ii ii iv ii ii ii iv i...

  • Page 32

    - 31 - connecting rod for the 501 model – 356-12-230 502 model – 450-12-230 roller – 353-12-012 crank pin – 355-12-141 353-12-012 450-12-141 inner diameter outer diameter outer diameter marked 1 marked a marked i 1 29.900 + 0.002 a 4.002 - 0.002 i 21.900 - 0.001 2 29.902 + 0.002 b 4.000 - 0.002 ii 2...

  • Page 33

    - 32 - assembling the engine before assembling the engine all its parts have to be washed with petrol and dried. The seating faces of the crank case halves and of the l.H. Side' cover have to be cleaned from the old sealing compound by careful scraping. Any unevenness on the seating faces should be ...

  • Page 34

    - 33 - 6. Screw the cam plate to the l.H crankcase half taking care of the location of the centring screw. 7. Locate the assembled main shaft, with the bottom, second and third gear pinions, into the l.H crankcase half / for model 502 do not omit to secure the second gear pinion with the spring ring...

  • Page 35

    - 34 - 10. Fit the lay shaft with the lay shaft third and top gear pinions 11. Insert the rod into the selector forks and tighten the securing screw. Fig.23. 12. Press the driving gear with hub into the r.H. Crankcase half. 13. Turn the crankcase over and press in the sealing ring with the spacer. 1...

  • Page 36

    - 35 - the assembly of the clutch and l.H side cover, the dynastarter, the clutch operating bracket and the l.H. Side cover has been described in the preceding paragraphs.

  • Page 37: C Y C L E  P A R T

    - 36 - c y c l e p a r t the cycle part of both the 501 and 502 nzeta models looks alike and consists of monocoque bodywork: reinforced in the rear portion for the fastening of the spare wheel brackets. The 502 model employs a new suspension of the pivoted rear fork which makes it impossible to repl...

  • Page 38

    - 37 - after disconnecting the chain connect an old chain to it and by removing the chain from the pivoted arm the, old chain is being pulled at the same time; the old chain will make the fitting of the, new, or serviced chain easier. Having removed the chain, carry out its maintenance, shorten it i...

  • Page 39

    - 38 - of ground over which the machine is ridden and the medium in which it is employed the chain has to be greased approx. After every 1,200 to 3,000 miles / 2,000 to 5,000 km/. First wash the chain in paraffin. After drying, place the chain for about 3 hours in a lightly heated graphite lubricant...

  • Page 40

    - 39 - guard will be completely separated from the fork. Now take out the pins from the pivoted arm and using puller s-20, drive out the bushes. Press the rubber bushes out of the fork. After replacing all worn parts, reassemble by proceeding in the reverse manner. Model 501-removal of the suspensio...

  • Page 41

    - 40 - towards the rear of the machine. To replace proceed in reverse manner. To dismantle the pivoted rear arm in this respect the two models differ. Model 501 will be described first. For the 501 model, the pivoted rear arm can be dismantled only when the power unit has been taken out of the bodyw...

  • Page 42

    - 41 - dismantling the headlamp - both models first slacken the screw and remove the headlamp assembly. Compressing the cap and rotating it clockwise take the cap off and together with it the bulb holder with the bulb. To replace the headlamp glass, proceed as follows: remove the cotter pin and turn...

  • Page 43

    - 42 - in model 502 remove the cotter pin thereby freeing the bodywork door. Removal of the pin will free the lock and this can now be taken out. The bodywork door will be freed after the cotter pin has been removed. To dismantle the catches in model 501, proceed in the same manner as for the instru...

  • Page 44

    - 43 - pushing out the joint, remove the gear change pedal. To reassemble, proceed in reverse manner. To adjust the gear change pedal position, slacken the rod lock nuts and either screw the rod into or out of the socket..

  • Page 45

    - 44 - e l e c t r i c a l e q u i p m e n t dynamo the dc 45 w 6 v dynamo serves as the source of the electric current. It supplies the current to the ignition circuit /terminal i a/ and into the lighting circuit /terminal 51/. The dynamo is six pole, shunt type fitted with an automatic voltage reg...

  • Page 46

    - 45 - pal voltage regulator 6 v fig. 28 the pal 6 v regulator and the mechanical setting of the individual contact gaps is the same as that of the 12v dynastart regulator. The difference between the 6v and l2v regulators is in the voltage and current coil winding which is always adapted to the volt...

  • Page 47

    - 46 - pal dynastarter details of design: the dynastart parts are similar to those in the 6v 45w dynamo. The rotor is provided with a winding, the outlets of which are soldered to the individual commutator plates. Inside the rotor there is a tapered opening for fitting on to the crank pin. On the ou...

  • Page 48

    - 47 - operation of the dynastart with the regulator and contactor starter with the ignition key in starting position the current flows from the two six volt 5 m s 12 starting batteries via the connected contacts in the switch box into the winding in the contactor, magnetising the contactor iron cor...

  • Page 49

    - 48 - dynamo with the engine running and the starting circuit disconnected, the starter field winding is without current and the dynastart operates as a dynamo with voltage regulator. The operation is similar to that of the 6v 45w dynamo with pal regulator. The remaining magnetism in the pole shoes...

  • Page 50

    - 49 - regulator with contactor - mechanical checking mechanical checking of the regulator with contactor has to be carried out in case of faulty regulator operation. The regulator has to be checked for completeness of parts, the contacts cleaned, metal filings and dirt removed from the regulating s...

  • Page 51

    - 50 - pal 02-9490.60 dynastart – technical data dynamo nominal voltage 12v operational voltage 13.5 v nominal output up to 100w nominal current up to 7.5 amps, operational voltage r.P.M. 1,700 starter nominal voltage 12v operational voltage at engagement torque 9 v minimum engagement torque at 20 5...

  • Page 52

    - 51 - lights the headlight is equipped with a two filament bulb, the bulb in the model with a dynamo is 25/25 w, that in the dynastart model is 35/35 w. Headlamp beam adjustment is by tilting the reflector after slackening the screw on the top of the headlamp nacelle. Having adjusted, the headlamp ...

  • Page 53

    - 52 - this workshop manual is an ocr copy of the original nzeta workshop manual as supplied to dealers throughout new zealand. It is an english translation of the cezeta workshop manual, and as such, some parts may not apply to nzeta models as supplied . Ian’s bike museum has attempted to change so...