AJS 350 1954, Руководство по эксплуатации и инструкция по использованию, Страница: 41 / 96

CARBURETTER ADJUSTMENT
To ascertain if the setting is correct (350 c.c. models only), a rough test Is to warm up
the engine and, with the ignition fully retarded and the air about three-quarters open,
gradually open the throttle to full open, during which the engine should respond without
a misfire, but, upon a sudden opening of the throttle, it should splutter and stop. (The
engine should not be run for more than a few seconds with the ignition fully retarded.)
NOTE—On 500 c.c. models the ignition is automatically retarded at low engine revs.
To check the setting of the pilot jet and its air control, warm up the engine, then, with
the ignition about one-third retarded and the air about three-quarters open, the engine
should idle positively and evenly when the throttle is almost closed. If it fails to do so,
adjust the pilot jet air screw inwards, or outwards, until even firing is obtained. (The
pilot jet air screw is at the base of the mixing chamber and its position is locked by a nut.)
This adjustment is not unduly sensitive, and it should be possible to obtain the correct
adjustment in a lew seconds. In the event of the adjustment of the airscrew failing to
provide the required result it is possible the pilot jet is obstructed with dirt. The pilot
jet is actually a passage drilled in the sprayer base, or choke, and is very small, so there
is always latent danger of this becoming choked.
Upon removing the float chamber and the large nut at the bottom of the mixing chamber,
the sprayer base can be pushed out of the mixing chamber and the jet can be cleared by
using a strand of fine wire.
Before concluding that incorrect carburation is responsible for heavy petrol consumption,
and before carrying out any of the tests and adjustments described above, it is most
Important to make sure the ignition is set correctly. Late ignition usually causes a
great increase in petrol consumption.
TWIST GRIP ADJUSTMENT
A screw is provided in one of the halves of the twist grip body to regulate the spring
tension on the grip rotating sleeve. This screw, which is locked by a nut, must bestrewed
Into the body to increase the tension.
The most desirable state of adjustment is that when the grip is quite free and easy to
operate but, at the same time, will stay in the position in which it is placed.
The complete twist grip can be moved on the handlebar by slackening the two screws
that clamp together the two halves of the body. The most desirable position is that in
which the throttle cable makes the cleanest and most straight path to the under-side
of the petrol tank.
Smooth throttle operation is assured by the provision of a cable oil nipple. At the first
signs of jerky action a little engine oil should be injected, applying the gun as near
vertical as possible (nozzle downward).
AIR FILTER
In locations, such as the United Kingdom, where the roads and atmosphere are
particularly free from dust, it is not considered necessary to have an air filter fitted to
the carburetter, but in countries where the atmosphere contains a very heavy dust
content, an air filter is essential in order to prevent abrasive wear.
The filter available (optional extra) for the conditions mentioned above is of the " Oil
Wetted " type, and this requires periodical servicing.
When servicing the air filter, withdraw the filter element. Thoroughly wash this in
petrol, paraffin or other suitable solvent and allow to dry. Then re-oil, using one of the
light oils (SAE-20), enumerated in the final table on page 14, and allow to drain before
replacing in the filter case.
Clean regularly at intervals of 1,000 miles, and renew the
element every 10,000 miles.
G—A.S.
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