Royal Enfield CONSTELLATION 1958, Workshop Maintenance Manual

Page: 68 / 106

SECTION G1f
Lucas Twin-Cylinder Magneto
Models K2F (42369) and K2F (42369B)
1. General
This magneto incorporates a wound rotating
armature and a high-energy permanent magnet
field system, this latter being cast integral with
the body. The unit is designed for 3-point flange
fixing.
Small breathing holes are provided in the
body of the magneto. These holes should not be
allowed to become blocked.
Provision is made for altering the ignition
timing by the manual control method, in which
the cam ring is moved relatively to the armature.
The lever controlling this movement is mounted
conveniently on the handlebars and is connected
by a control cable to the magneto.
2. Routine Maintenance
2 (a). Lubrication
To be carried out every 3,000 miles.
(i) Wipe out the outside of the magneto to
remove dirt or grease, and then take off the
contact
breaker cover. Unscrew the
hexagon-headed screw in the centre of the
contact breaker and withdraw the contact
breaker from its housing. Push aside the contact
breaker arm retaining spring of the K2F (42369)
type unit, and in the case of the later K2F
(42369B) model, prise off the special locking
plate from the contact breaker arm pivot pin,
taking care not to lose the insulating washer
beneath it.
Slacken the screw which retains the contact
breaker arm spring. The contact breaker arm
may then be lifted from its pivot.
Wipe away any dirt or grease from the
contact with a petrol-moistened cloth. If
necessary, use a very fine carborundum stone to
polish the contact, re-cleaning afterwards with a
petrol-moistened cloth. Smear the pivot pin with
a little Mobilgrease No. 2 before refitting the
contact breaker arm.
Remove the cam ring, which is a sliding fit in
its housing, and lightly smear inside and outside
surfaces with Mobilgrease No. 2. Both removal
and refitting of the cam can be made easier if the
handlebar control lever is half retarded, thus
taking the cam away from its stop pin. Apply
one or two drops of thin machine oil to the felt
cam lubricator in the housing. Refit the cam,
taking care that the stop peg in the housing and
the plunger of the manual timing control engage
with their respective slots.
Refit the contact breaker. This can be made
easier if the contact breaker heel is away from
the cam lobe; turn the engine until this is so. The
key on the projecting part of the contact breaker
base must engage with the keyway in the
armature shaft. Refit the hexagon-headed screw
and tighten with care. It must not be slack, nor
must undue force be used.
(ii) Bearings. The main bearings of the
magneto are packed with grease during
manufacture and need no attention until a
general overhaul is undertaken.
Section G1f Page 1
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