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Defect
Cause
Removal
Changing from 1
st
to 2
nd
gear takes
very long or it does not take place at
all.
When the 2
nd
speed clutch is sliding
it is not allowed to drive more than
1km. High temperature can reduce
the lifetime of driving belt.
Slipping 2
nd
speed clutch.
1.
Dirt or oil on friction areas.
2.
Water on friction areas.
3.
Interchanged 2
nd
speed shoes. It is also
possible that the lining touches the
drum on the less effective trailing
side.
1.
Remove dirt, degrease drum and
linings with suitable degreasing agent.
Then run in the clutch (formation of
final friction layer). Find cause of
contamination (defective GUFERO
sealing ring, O ring, burrs).
2.
Without dismantling dry the clutch by
letting it slip.
3.
Replace shoes correctly or wait till
lining settles down on the whole
working surface. Gears have to be
changed about 20 to 25 times before a
new lining, made so that it touches the
drum on the leading edge, has settled
down to enable the function of the
whole working surface.
Changing from 1
st
to 2
nd
gear takes a
shorter time than normal or a very
short time. Exceptionally, the moped
even starts from rest in 2
nd
gear or a
change from 2
nd
to 1
st
gear takes
place when riding uphill.
Imperfect control of retraction of 2
nd
speed shoes by regulating driver.
1.
check moveability of inner driver
(regulating driver contact under load).
Hard chrome plated lands on inner driver
must be bright & undamaged.
1.
This defect can be identified and also
removed by replacing inner driver
with a new one.
Changed properties of this contact can also be brought to light by a comparrison test of
1
st
to 2
nd
gear change under load (at full throttle):
A)
Moving along in 2
nd
gear, decelerate by applying the brakes to change down from
the 2
nd
to the 1
st
gear. After releasing the brakes, the transmission will change
smoothly from the 1
st
to the 2
nd
speed.
B)
Then decelerate by throttling down. This will release the regulating driver which
will turn to the opposite side. On acceleration, the changing up from the 1
st
to the 2
nd
gear is different – more sudden than in point A). This indicates that the regulating
driver does not set readily on the inner driverand that the contact areas (lands) are
not in satisfactory condition.
2.
The inner driver must turn and bear
against the working surfaces with a
certain peripheral clearance.
3.
Defective chromium layer between
regulating driver and brass layer on
clutch shoe and /or destroyed brass
layer. Oxides formed there by
pressure increase friction between the
parts.
Other harmful factors:-
4.
Increased humidity of air in the space
of clutches.
5.
High working temperature of 2
nd
speed clutch built up by changing
gears in rapid succession (fifteen and
more times).
6.
Thick layer of particles of abraded
friction material in the form of scales
covering the working surface.
2.
Renew the parts. It is not
recommended to thin down faces of
the parts by grinding.
3.
Renew regulating driver, renew shoes.
4.
Heat the space of clutches by a short
ride without changing gears.
After every washing of the moped, start
the engine and let it warm up.
5.
A 10 to 15 second ride will suffice to
restore the original properties of the
clutch. This is actually no defect but a
normal property of friction linings.
6.
Find and remove the cause of lining
abrasion. Remove the layer
mechanically, for instance with fine
abrasive (emery) paper, taking care
not to change the shape of the settled
down (bedded) lining.
Optimum gear change in model 210 moped, 2
nd
gear – 40 km/hr. at full throttle acceleration.
(2
nd
speed clutch warmed up to service temperature).
After starting from rest, the 2
nd
gear is engaged within a distance of 26 metres.
Permissable gear-change tolerance limits: +30 m, -5 m.
Engagement of 2
nd
gear begins at a distance of 18 meters and is complete in about 1.5 to 2 seconds.
A cold 2
nd
speed clutch prolongs the distance by 9 meters (first to forth gear change).
An overheated 2
nd
speed clutch shortens the distance by 3 meters.
According to speedometer readings, the moped should attain about 24 km/hr. in 1
st
gear at full throttle and
the change to the 2
nd
gear should be completed at a speed of about 28 km/hr.
ZVL model 210 Workshop Manual Page 28 & 29
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