Ignition Timing - Stihl 064 Service Manual

STIHL 064, 066
5.1.6.1

Ignition Timing

Ignition timing on the transistor - controlled
magneto ignition systems is fixed at 2.6 -
3.4 mm (0.10" - 0.13") B.T.D.C. at 8,000
rpm on the 064 and 2.9 - 3.9 mm (0.11" -
0.15") B.T.D.C. at 8,000 rpm on the 066. It
is not adjustable. However, in view of the
permissible tolerances in the electronic
circuit, it may vary between 2.5 - 3.5 mm
(0.09" - 0.14") B.T.D.C. at 8,000 rpm.
Since there is no mechanical wear in these
systems, ignition timing cannot get out of
adjustment. However, an internal fault in the
circuit can alter the switching point in such a
way that a spark test will still show the
system to be in order although timing is
outside the permissible tolerance. This will
impair engine starting and running behavior.
5.1.6.2 Removing and Installing
Top:
1 = Wire retainer
2 = Wire to LED (066 only)
3 = Short circuit wire
Bottom:
Digital ignition module mounting screws
- Remove fan housing - see 5.1.5.
- Disconnect short circuit wire and
wire to LED (on 066) from tags
on ignition module and take them
out of the retainer.
- Remove the ignition module
mounting screws.
Top:
Pulling unscrewed ignition lead
out of ignition module
Bottom:
Removing wire retainer from
ignition module
- Unscrew the ignition lead from
the contact pin. To do this, rotate
the ignition module and pull the
lead out of the high voltage out
put.
- If necessary, remove the wire
retainer from the module.
Note: The digital ignition module
can be installed in saws from ma-
chine number X 18 761 250, or
saws with a new crankcase, which
have a third mounting boss for the
yoke of the digital ignition module.
54