Help with F-7 Diesel Loco

[man63f]

My son was gifted three beautiful Williams F-7 Diesel locomotives.  We run basic Lionel trains (nothing fancy) and we do not have the knowledge about trains that most everyone on this board does.  Here's my question.  The F-7 locomotives run great, but will only run for a short period of time (maybe for 1 minute) and then stop.   We have to turn off the power and turn it back on to get it to start up again.  It's almost as if there is a time feature built in.  I'm not experienced to know if this is the case.  Can anyone provide troubleshooting tips (in lay terms) to help us figure out what may be causing this?  Thank you.

[671]

Hi man631,
         
           671 here. 

This sounds like your power source, the transformer may be of a very low capacity ( 40-80-watts ).  This may be the problem. The transformer may be tripping on its' safety overload device.
The motors, the lights within the cars and any other 'load' that goes through the transformer adds to the strain upon the transformer.
Shutting off the transformer is a technique to reset the tripped circuit.

Try turning off all of the loads on that transformer, place just the one loco onto the track and see if it runs. If it does, the  low powered transformer is the problem.  Time to buy a more powerful transformer.

                                                Hope this helps...671

[Len]

I suspect your using a Lionel 80 watt transformer, with the orange handle on the side. They are intended for Lionel starter sets, and can't handle the current load of larger, and heavier, two motor locomotives.

The first paragraph on page 2 of the F7A instructions recommends a transformer rated at a minimum of 90 watts:
https://www.bachmanntrains.com/home-usa/dwg/dwgs/F7A_Powered.pdf

Something like the MRC "Throttlepack AC 100", a 100 watt transformer, should work okay.
https://www.hobbylinc.com/mrc-throttlepack-ac-model-train-power-supply-transformer-0001311

If you're going to be running lighted passenger cars, you'll probably want something a bit bigger. Especially if they're the heavier aluminum body cars.

Len