Royal Enfield 350 BULLET 1949, Workshop Maintenance Manual

Page: 38 / 102

ROYAL ENFIELD WORKSHOP MANUAL
Section G1c Page 1
SECTION G1c
Lucas Magdyno
Model MOIL for Single Cylinder Engines
1
. General .
The Magdyno is a base-fixed magneto
and dynamo unit, the body of the magneto
portion being arranged to carry a standard
strap-fixed dynamo. A shock absorbing drive
is arranged between the magneto and
dynamo portions. The magneto portion has a
wound rotating armature and a high energy
magnet case integral with the body.
The shock absorbing drive is incorporated
in the larger of the two gears which transmit
the drive from the magneto shaft to the
dynamo and is shown exploded in Fig. 1.
This drive, whilst permitting maximum
dynamo output to be obtained, reduces peak
shock loadings on the teeth of a bakelised
fabric gear to a minimum value. The drive is
taken from metal gear centre A, keyed to the
magneto shaft, to fabric gear B by means of
friction plate C and clutch spring D. A peg
projecting from gear centre A prevents
relative movement of the gear centre and
tension spring D. In the event of a back-fire
or an electrical short-circuit, slip will occur
between the contacting surfaces of fabric
gear B and gear centre A.
2. Routine Maintenance
2(a). Lubrication
To be carried out every 3,000 miles.
The cam is lubricated by a wick located in
the contact breaker casting (see Fig. 2). To
reach the wick, remove the backing spring
and spring arm by withdrawing the single
securing screw. The wick is carried in a
hollow hexagon headed screw which can
now be withdrawn. Take care not to lose the
insulating washer or tube. Moisten the wick
with a few drops of thin machine oil and
refit the hollow screw.
At this stage, bend back the brass locking
tag from the hexagon head of the contact
breaker securing screw and withdraw the
screw. The contact breaker can now be
removed. Take out the tappet which actuates
the spring arm and lightly smear it with thin
machine oil. Extract the wire ring and
remove the face cam. Lightly smear both
sides of the cam with Mobilgrease No. 2.
Refit the cam, taking care that the stop
peg in the housing and the plunger of the
timing control engage with their respective
slots. Note that a recess is provided for the
"eye" of the wire ring.
Check that the tappet moves freely in the
contact breaker casting.
Thread the special tag washer on the
contact breaker securing screw and place the
flat edge of the washer against the location
provided for it in the contact breaker casting.
Tighten the screw and lock it by bending the
tag washer against one of the hexagon flats.
Wipe away any dirt or grease from the
contacts with a petrol-moistened cloth. If
necessary, use a very fine carborundurn
stone to polish the contacts, re-cleaning
www.hitchcocksmotorcycles.com