Dynamic Timing - Honda CB350 Repair Manual

TUNE—UP 31
as the engine. Switch the meter to its
lowest range. When the points are closed
the resistance should be less than 0.1
ohm; at the instant the points begin to
open, the ohmmeter needle will indicate
high resistance. The ignition must be
turned off when using an ohmmeter as
feeding voltage through the meter will
damage it.
Regardless of the type of tester used,
the hookups are similar: one of the leads
is grounded to the engine, the other is at—
tached to the points primary wire termi—
nal, the points spring, or to the primary
wire itself.
NOTE: Points must be cleaned and
gapped before checking timing. Dirty
points will cause inaccurate readings.
The method of adjusting the timing is
the same regardless ofthe type of equip—
ment used. The left cylinder is set first
and timing is adjusted by moving the
base plate. The points on the left—side of
the base plate are those for the left cylin—
der. After the left cylinder is correctly
timed, the right cylinder can be checked,
and adjusted if necessary. To adjust the
right cylinder timing, the point gap is
varied so that the points open at the in—
stant the timing marks align. A change in
the point gap of 1.0 mm (0.004 in.) will
change the timing 10°. Increasing the
point gap will advance the timing, while
decreasing it will retard the timing.
If correct timing cannot be ac—
complished with both point gaps set in
the correct range of 0.3—0.4 mm
(0.012—0.016 in.), the points should be re—
placed.
DYNAMIC TIMING
1. Remove the alternator cover so that
the timing marks are visible.
NOTE: A white grease pencil or some
paint can be used on the rotor and sta—
tor timing indicator marks to increase
their visibility under the strobe light.
2. Hook up the timing light according
to the manufacturer's instructions. Most
lights use the vehicle's own battery as a
power source.
3. Start the engine, aiming the light on
the rotor. Note the following:
a. At idle, the "LF" (left cylinder)
mark or the "F" (right cylinder) mark
on the rotor should line up with the
timing indicator on the stator, depend—
ing on which plug the strobe light is
connected to;
b. As the revolutions increase, the
"LF" or the "F" mark should be seen
to move in a direction opposite that of
the crankshaft rotation;
c. Finally, at full advance (about
3,200 rpm and above), the twin rotor
marks must line up with the timing in—
dicator mark on the stator.
apm"
Rotor timing marks: (1) firing point; (2) stator
index; (3) full advance firing point
4. The full advance reading is the most
important. Ifthe rotor marks and the sta—
tor indicator do not align, proceed as fol—
lows:
5. Time the left cylinder first. Remove
the points cover. Loosen the two serews
which secure the breaker base plate just
enough to allow the plate to be turned.
Using a thin screwdriver applied at the
pry point provided, rotate the plate in the
direction necessary so that the timing
marks align.
Rotating the plate clockwise advances
the timing; rotating the plate coun—
terclockwise retards the timing.
Tighten the base plate screws and
recheck the timing.
6. Connect the timing light to the right
cylinder and check the timing as for the
left cylinderthis time using the "F" mark
on the rotor.
If the right cylindertiming is incorrect,
loosen the two screws which secure the
right—side points to the base plate. Open
or close the point gap so that the timing
marks align as the points open.
7. After the ignition timing is set, re—
check the point gaps. Both must still be
within the proper specification (0.3—0.4
mm/0.012—0.016 in.).
If either gap is not within this value,
increase or decrease it as necessary so