Triumph SPEED TWIN 1945 Workshop Instruction Manual page 69

I G N I T I O N T I M I N G (MAGNET
(Assuming that the magneto
is
in position and the timing cover i s removed).
Magneto Wheel. Unscrew the securing nut and screw i n t o the gear centre the
w,thdrawal tool DA50/1 which is supplied with the toolkit. When the t o o l is i n
position, tighten the centre bolt and the gear will be withdrawn from the shaft.
set
the contact breaker points t o ,012 ins. fully open.
Sparking Plugs. Remove both plugs.
I
p i s t o n Positioning. Unscllew the rocker inspection cap.
Engage
TOP
gear and
then rotate the rear wheei in the correct direction for forward travel, watching the
valve operation i n the
L.H. (DRIVE SIDE) cylinder. When the INLET valve closes,
continue gently t o rotate the rear wheel until the piston reaches the t o p of the
rrroke (this is known
as
"TOP DEAD CENTREw-T.D.C.). The correct piston
position can be felt with the timing stick by rocking the
r e a r
wheei t o and fro. W h e n
the T.D.C. has been found, mark the lowest part of the timing stick which is visible
at'eye level and remove the stick; make
a
further mark (&"or (8 mm. o r 9.5 mm.)
as
the case may be) above the
f i r s t
mark. N o w re-insert the timing stick i n t o the
cylinder and rotate the rear wheel backwards until the piston has fallen about 1"
(2.5 cms.), then reverse the rotation and slowly bring the piston up t o the desired
mark on the timing stick. This procedure eliminates any e r r o r due t o backlash in the
tim~ng gears.
CAM IN
FULLY
ADVANCED
POSlTiON
Fig. 22.
M A G N E T O IN T I M I N G P O S I T I O N
67