JAWA 50 Specification And Operator's Manual - page 8
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4. TYRES
The life of the tyre depends 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 in the cover wall
cord threads breaking.
The excess in the front tyre should amount 1.5 atm
(21 p.s.i.) and in the rear one 1.9 atm. (27 p.s.i.)
with one passenger. In case of two passengers the
excess pressure in the front tyre should amount 1.9
atm. (21 p.s.i.) and in the rear one 2.3 atm. It is
advisable to check the pressure with the tyre
pressure gauge. Remember, that oil, petrol and hot
sun is harmful for the tyres. Examine the tyres
from time to time and remove all objects stuck in
the pattern. To check the tyre valve for leakage,
unscrew the valve cap and moisten the tyre valve.
Should any bubbles appear, the valve is leaky. In
such a case tighter one valve core using the slotted
valve cap for one purpose. If this is not sufficient,
remove the valve core and replace it. A punctured
tyre has to be patched. To remove the tyre from the
rim proceed as follows;
Unscrew the valve core - thus letting the remainder
of air out. Unscrew the nut fastening the valve to
the rim. Lay the wheel in a horizontal position and
press the tyre edge well into the rim base at a point
diametrically opposite to the valve (Fig. 16).
Using the tyre levers slip the cover edge over the
rim edge (Fig. 17). Take care not to pinch the tube
and thus damage it. Having slipped all the cover
circumference over the rim edge press the valve
completely out of the rim base and remove the
tube.
Having screwed in the valve core and inflated the
tube partially the punctured spot is best located by
plunging the tube into water. Mark the punctured
spot (e. g. with a copying pencil),dry the tube and
repair it as follows:
Rub the punctured spot slightly with a piece of
sandpaper. Smear the rubbed spot with rubber
solution. Allow the solution to dry and only then
press on the patch first removing its protective
coating. Press the patch well on to the tube.
Examine the outer cover carefully and if the nail
that caused the puncture is still in, remove it.
Fitting the tyre. Inflate the tube partially, insert it
into the cover, one edge of which has remained in
the rim, push the valve through the rim hole and
secure it by its nut (do not tighten).
Slip on the cover side over the rim edge beginning
opposite the valve, work with hand or foot and tyre
lever both sides towards the valve. Proceed
carefully in order not to damage the tube. Tyre
patching is an emergency remedy only. A
permanent repair is best entrusted to a workshop.
Entrust the repairing of tyres damaged by sharp
gravel or glass to a workshop.
5. ADJUSTING THE CHAIN
Slacken the rear wheel spindle i.e. the spindle
securing nut using spanners # 7 and # 27.Slacken
the chain adjuster nut and tighten the chain
adjusters uniformly, move the rear wheel spindle
thus tensioning the chain. Never use force when
handling the adjusters in order not to damage the
thread. When the chain has been adjusted, tighten
the wheel nuts and the chain adjuster nuts. A
correctly adjusted chain has a slack of 1 to 2 cm
(3/8 to 3/4 in.). Make sure that the wheels are in
line. Check and, if necessary, adjust the rear wheel
brake. Check the chain tension every 600 miles
(1,000 km).
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JAWA 50 type 20, 21, 23, 23A Owners Handbook page 26 to 29
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