Cub Cadet MTD 70 Series - Manual (Page 93)

Ignition System
87
7e. If further investigation is required, remove the
recoil assembly by following the steps
described in Chapter 6: Starter.
7f. Visually trace the wire from the stop switch to
the connector on the module, and inspect the
wire for any damaged insulation or potential
contact with ground.
7g. Unplug the wire from the spade terminal on the
module or unplug the insulated bullet connec-
tors, depending on the production date of the
engine, and check continuity to ground from the
female terminal on the wire from the switch.
Resistance (Ohms) should be zero with the bail
released or the switch turned off. See Figure
7.5.
8. Resistance (Ohms) should be infinite (O.L) with the
bail released. See Figure 7.6.
8a. If the switch and wire work properly, and the
connection is good at the spade terminal, but
releasing the bail or turning off the switch fails
to stop the engine, then the problem lies within
the module.
9. The module
9a. Normal performance of the coil is to produce at
least 10,000 volts at starter-rope pull-through
speed. See Figure 7.7.
9b. Presence or absence of strong spark, with the
stop switch and wire known to be good, is gen-
erally enough to identify the ignition coil as good
or bad. Resistance readings may help confirm
the source of the failure, but are generally
meaningless because they only measure a
small part of the module.
NOTE: Presence of a weak spark maybe the result of an
improper air gap. The air gap space should be
0.012” - 0.020” (0.3 - 0.5 mm).
Figure 7.5
Safety bail in OFF
position, Module
primary windings
are grounded
Figure 7.6
Safety bail in RUN
position, Module
primary windings
not grounded
Figure 7.7
Inexpensive spark gap tester
provides usable information