Lehman 120 won't switch off - overheat?

[Gumbalaya]

Engine won't switch off from neither stations, cabin or fly bridge.
Manually switched off the magnetic switch at the engine.
Works now fine again (weird).
Mech told me might be overheat (engine ran >4h that day).
Any experience, advice?

 

[LaBomba]

I would start by checking all wiring connections that are common to the two stations. Could be that it is just a loose wire.

 

[kchace]

The Lehmans require the "ignition" circuit be powered in order to be able to energize the shutdown relay. If for any reason that circuit lost power (battery switch off, key switch off, or loose wire, etc) both stop buttons would not work.