Matchless 1964 G12 650, Инструкция

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TO RE-TIME T H E I G N I T I O N — T W I N S (MAGNETO MODELS)
Before proceeding to time the ignition it is advisable first to check the contact breaker
point gap, which should be from ·012" to ·015" and correct it if necessary.
Having loosened the nut securing the magneto driving pinion, release same from the
tapered end of the magneto shaft by means of a special extractor, as described on page 42.
Remove the inlet rocker cover from the off-side cylinder head.
Remove the sparking plug from the off-side cylinder.
Insert a small rod into the sparking plug hole and, feeling the piston with the end of this
rod, carefully turn the engine in its normal direction of rotation until the piston is exactly
at the top of the stroke after the inlet valve has closed.
Hold the rod vertical in plughole, mark the rod where the plug boss registers. Take out
the rod, make another mark higher up
a
" for the 500 c.c. twins or
Y
" for the 650 c.c
models. Re-insert the rod, turn engine backwards until the higher mark registers with
the plug boss. This applies also to the standard twins.
Place the ignition control lever in the fully advanced position.
Next, taking care not to disturb the piston position, turn the magneto in a clockwise
direction (looking at the contact breaker end of the magneto) until the contact breaker
points are just about to separate by reason of the fibre block on the bell crank lever
commencing to mount the lower cam hump.
The exact point of separation is best found by inserting between the contact points
a strip of thin tissue paper when the separation point can be determined by the paper
just being released with a light pull.
Having obtained this position, press the magneto driving gear on to Its taper with the
fingers and lightly tighten the securing nut.
It is next advisable to re-check the setting by again turning the engine to the position
at which the piston is
a
” before the top of the firing stroke, re-inserting tissue paper
between the contact points and confirming that same can be released with a light pull.
Upon being satisfied that the setting is correct securely tighten down the nut fixing
the magneto driving gear.
a
" = 39°
Y
" = 35°.
NOTE—If a speed kit is used, or pistons with a compression ratio of 10·25 to 1, the
maximum ignition advance is 29°.
Illustration 20
Ignition timing
41
41