Troubleshooting The Stop Switch - MTD 61 Series Shop Manual

61, 65 and 70 Series Vertical Shaft Engines

Troubleshooting the stop switch

NOTE: the stop switch could be mounted near the
carburetor or if the engine is equipped with
an engine brake, the stop switch will be
located on the engine brake. The switch is
designed to ground out the module.
To test the stop switch:
7a. Locate the terminal that connects the stop
switch wire to the primary windings of the igni-
tion module. See Figure 7.2.
7b. Connect an Ohm meter between the terminal
and a ground point. The reading should
approach zero when the bail is released or the
switch is turned off, closing the contacts. See
Figure 7.3.
NOTE: If the reading is high, the contacts may be
burnt or there is a bad ground to the switch.
This could prevent the engine from shutting
down rapidly.
7c. The reading should be high when the bail is
pulled down or the switch is in the run position,
reflecting the resistance in the primary wind-
ings of the ignition module. See Figure 7.4.
NOTE: If the reading is low, the module is shorted to
ground and may not produce a spark. The
wire will need to be traced back to the mod-
ule to find the short.
7d. Alternatively, a jumper wire could be connected
to the same locations. Use a commercially
available spark checker to see if the ignition is
working or not.
• If the jumper disables the ignition, but releasing
the bail does not, the problem lies in the switch.
• If the jumper does not disable the ignition, then
the wire that connects the switch to the ignition
module may have a fault, or the ignition module
itself may be faulty. Further investigation is
required.
• If the problem is a lack of spark when the bail is
pressed against the upper handlebar, discon-
nect the wire from the switch using a 7mm
wrench. Isolate the wire from incidental contact
with ground, and test the ignition. If it fails to
spark, the wire may be shorted or the ignition
may be at fault. Further investigation is
required.
86
Stop switch
Figure 7.2
Ground connection
Safety bail in
OFF position
Figure 7.3
Ground connection
Safety bail
in RUN
position
Figure 7.4
Wire to
ignition model
Stop
switch
connection
Stop switch
connection