Austin-Healey Sprite User Manual

GENERAL MAINTENANCE
AUSTIN-HEALEY SPRITE
If this operation has the effect of stopping the engme it
is an indication that the mixture setting is too weak.
If an appreciable speed increase occurs and continues to
occur when the piston is raised as much as ~ in. (6 mm.)
it is an indication that the mixture is too rich.
(6) When the rear carburetter mixture setting has been carried
out correctly release its throttle adjusting screw so that
it is clear of the stop and the throttle is completely closed,
and lift the piston $ in. (13 mm.) to render it inoperative.
Then repeat the jet-adjusting operations on the front
carburetter.
(7) When both carburetters are correctly adjusted individually
for mixture strength the throttles of each should be set so
as to give the required slow-running and synchronisation.
A. 12-volt battery provides the current necessary to operate the
IGNITION SYSTEM
ignition system. A high voltage is induced by the coil, and the
distributor, as its name implies, distributes this voltage to the sparking
plugs in the correct firing sequence.
etc.
Distvtbutort The DM2 type Lucas distributor is fitted with an
automatic timing control operated by centrifugal force together
with a vacuum timing control operated by the depression in the
engine induction manifold. The combined effects of the two
controls gives added efficiency over the full engine operating
range, with a corresponding economy in fuel consumption.
A micrometer adjuster is also provided in order that fine
adjustments to timing may be made to allow for changes in
running conditions, e.g. state of caibonisation, change of fuel,
To gain access to the distributor contacts for cleaning and re-
facing, first remove the distributor cover and rotor arm. Next,
unscrew the nut on the terminal post, lift off the spring and
remove the contact adjusting screw '1', after which both contacts
inay be removed.
Examine the contacts, which must be free from grease or oil.
lf they are burned or blackened, clean them with a very fine
carborundum stone or with very fine emery cloth. Afterwards
wipe away any trace of dirt or metal dust with a petrol moistened
cloth.
If the contacts are badly burned, they should be renewed.
Replacement contacts must only be fitted in pairs.
When refitting the contacts take care that the fibre insulating
washer is replaced in its correct position.
Slow-running and Synchronisationt Screw each throttle lever
adjusting screw so that its end is only just making contact with
the web on the carburetter body, then give each screw one full
turn exactly.
Start the engine, which will now idle on the fast side.
Unscrew each throttle lever adjusting screw an equal amount,
a fraction of a turn at a time until the desired slow-running
speed is achieved.
Correct synchronisation can be checked by listening at each
carburetter air intake in turn through a length of rubber tube
and noticing if the noise produced by the incoming air is the same
in both. Any variation in intensity of the sound indicates that
one throttle is set more widely open than the other — the louder
sound indicates the throttle with the greater opening.
When the same intensity of sound is produced by both car-
buretters the intercoupling shaft clip should be tightened up
firmly to ensure that the throttles work in unison.
Since the delivery characteristics, when both carburetters
are operating together, vary somewhat from those existing when
each is working separately it will be found necessary to check
them again for correctness of mixture strength by lifting the
pistons in turn as described in 'Adjusting the jets,' making such
adjustments of the jet adjusting screws as are required to balance
the mixture strength and to ensure that it is not too rich.
1. Contact adtusnng scte»»
2. Contact adjustmg slot.
3. Cam and dna e shajt
oiling point.
4. Contact points.
5. Micrometer adjuster.
The Distributor
H 30. (5) 193.A.
43
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Austin-Healey Sprite Specifications

General

Brand	Austin-Healey
Model	Sprite
Category	Automobile
Language	English