Stop Switch - MTD 78 Series Shop Manual

78/83/90 Series Horizontal Shaft Engines

Stop switch

All MTD horizontal engines that are in use in North
America have a stop switch built into the throttle lever
assembly. MTD engines used on snow blowers have an
additional stop (ignition) switch in the engine shroud.
To test the stop switch (throttle):
1. Remove the control panel by following the steps
described in Chapter 3: Air Intake Systems.
2. Test the remote (ignition) stop switch first by follow-
ing the procedures described in the next section of
this chapter.
3. Disconnect the lead that runs from the module to
the stop switch. See Figure 7.2.
NOTE: The blower housing was removed for picture
clarity.
4. Connect one lead of a digital multimeter to the lead
going to the stop switch. Connect the other lead of
the digital multimeter to a good ground.
5. Set the multimeter to the ohms (Ω) scale.
6. Operate the throttle lever while watching the multim-
eter.
• When the throttle is all the way to the right (stop),
the multimeter should read at or near 0.0Ω, indicat-
ing continuity. See Figure 7.3.
• When the throttle is all the way to the left (full throt-
tle), the multimeter should not show continuity.
See Figure 7.4.
82
Disconnect switch
Figure 7.2
Switch lead
continuity
Figure 7.3
no continuity
Figure 7.4
Throttle lever