Adjustment Of Contact Breaker Setting; Cleaning Contacts; Removal Of Contacts For Cleaning; High Tension Pick-Up - Triumph SPEED TWIN 1945 Workshop Instruction Manual

Magneto Maintenance
A d j u s t m e n t of C o n t a c t B r e a k e r Setting.
The setting o f t h e contact breaker
must be checked every 3,000 miles (5,000 kms.). T o d o this, remove the contact
breaker cover and t u r n the engine until the contacts are seen t o be fully open.
Check t h e gap w i t h afeeler gauge having a thickness of 0.012"-0.015" (0.30 t o 0.40 rnm.).
a gauge f o r this purpose is provided o n t h e spanner usually supplied w i t h each
magneto. I f the setting is correct, the gauge should be a sliding
fit,
b u t i f the gap
w i d t h varies appreciably from the gauge thickness
it
must be adjusted. Keep t h e
engine i n the position giving maximum separation of the contacts,~lacken t h e locknut
and t u r n t h e contact screw by
its
hexagon head until the gap
is
set t o t h e gauge.
Tighten t h e locknut and re-check t h e setting.
C l e a n i n g Contacts. .Every 6,000 miles (10,030 kms.), take off the contact breaker
cover and examine the contact breaker. D i r t y o r pitted contacts can ,be cleaned
w i t h a tine carborundum stone, or, if this is not available, very fine emery sloth can
be used.
W i p e away any d i r t o r metal dust w i t h a cloth moistened w i t h petrol. Contact
breaker springs should be examined and any rust removed. To render the contacts
accessible f o r cleaning, proceed as outlined below.
After cleaning, check the contact breaker setting.
R e m o v a l o f C o n t a c t s f o r Cleaning. Unscrew the contact breaker securing screw.
Carefully lever t h e contact breaker off the tapered shaft on which
it fits.
Push
aside the locating spring and l i f t the rocker arm OH
i t s
pivot, when
it
w i l l be possible
t o clean the contacts. When replacing the contact breaker, check that t h e pro-
jecting key, o n the tapered portion of the contact breaker base, engages w i t h t h e
keyway cut i n the armature spindle, otherwise the timing of the magneto w i l l b e
affected. Replace the contact breaker securing screw and tighten w i t h care.
H i g h T e n s i o n Pick-up.
About every 6,000 miles (10,000 kms.), remove t h e high
tension pick-up. W i p e the moulding w i t h a clean d r y cloth.
Check that t h e
carbon brush moves freely i n i t s holder. b u t take care n o t
t o
stretch t h e brush spring
unduly.
If the brush
is
dirty, clean
it
w i t h a cloth moistened w i t h petrol. If t h e
brush
i s
w o r n t o within
+"
(3.0 mm.) of the shoulder
it
must be renewed.
Before re-fitting the high tension pick-up, clean t h e slip ring track and'flanges b y
pressing a soft d r y cloth on the ring w i t h a suitably shaped piece of wood, while t h e
engine
i s
slowly turned.
R e n e w i n g H i g h T e n s i o n Cables. When high tension cables show signs of-cracking
o r perishing, they must be replaced, using 7 mm. rubber covered ignition cable.
T o replace a high tension cable proceed
as
follows:-
Remove the metal washer and moulded terminal from t h e defective cable. Thread
the new cable through the moulded terminal and cut back t h e insulation for about
F
(6.0 mm.). Pass the exposed strands through the metal washer and bend t h e m
back radially. Screw the terminal i n t o t h e pick-up moulding.