JAWA ZVL 210 Service Manual - page 24

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VI. CAUSES OF DEFECTS AND THEIR REMOVAL

A. ENGINE

 Loss of power

1. Clogged air cleaner.

Engine will not start

2. Clogged exhaust silencer.

1. Shut fuel cock.

3. Damaged crankcase sealing ring.

2. Empty fuel tank.

4. Damaged piston, cylinder or piston rings.

3. Choked fuel hose, strainer or fuel jet. Water

5. Leaky cylinder head.

    in float chamber.

 6. Maladjusted ignition advance.

4. Faulty ignition --  carbon deposits on spark

    plug electrodes, defective spark plug insulator,

Engine power is satisfactory, but acceleration is

    excessive plug point gap, defective thyristor device

 poor or peak speed cannot be attained.

    defective ignition coil or stator carrier.

5. Over flooded engine.

1. Brake shoes are fouling the drums.

    Remedy: Shut off the fuel cock and work the

2. Under inflated tyres.

pedals with the machine on its stand or pedal along

3. Slipping starting clutch or 2

nd

-speed clutch

till the engine fires. Use the decompressor if the

moped is fitted with it. Then open the fuel cock.

It may also be necessary to unscrew the spark     

B.   TRANSMISSION

plug and clean it and to turn the engine several

times to expel excessive fuel through the spark

plug hole. Reinstall the spark plug and repeat the

This chapter deals with the less frequent defects

starting procedure.

which can occur in operation.

6. Slipping or defective starting clutch. This you

can ascertain by removing the crankcase cover on

As regards identification of causes of incorrect

the ignition side when you will be able to see

function of 2

nd

-speed engaging mechanisms,

whether the crankshaft with the rotor is rotating.

it is assumed that a rider of the specified weight

rides on the moped with correctly inflated tyres on

a level road in calm weather and that the moped

Engine runs erratically                            

has no contributory rolling resistance as, for in-

stance, maladjusted brakes, and that the secondary

1. Overheated engine,                               

transmission mechanisms have not been interfered

2- Faulty spark plug, 

with, e.g. by exchanging the original sprocket for

3. Partly obstructed fuel supply or choked main jet

another one with a different number of teeth.

4. Leaky crankcase.

5. Faulty cable terminal.

6. Faulty ignition.

7. Imperfectly vented fuel tank.

ZVL model 210   Workshop Manual   Page 25                    

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