Lionel fastrack with burnt spot

Look at the bottom of the track to determine if something underneath shorted the center rail and outside rail. If not, it was most likely a derailment or playing accident that sparked the rail and sat there for a while.

My grandson "sparks" the trains, but I am using a Powerhouse 180 that kicks quickly.

Which transformer are you using?

It's not typical.

It's probably the CW-80. The breaker will kick fast enough. I would suspect something laying on the track or under the track when power was applied or a misaligned engine where the front roller(collector) could touch the outside rail or a car truck axles.

The construction of the track piece doesn't provide a good spot for the outside rails and center rail to contact and short.

However, there is a wire connector location that sometimes has the center connector over the ground bar. A loose or uninsulated center wire can then touch the bar the joins the outside rails electrically.

Whatever the cause, you are running. Be careful with the connections and a little education about not sparking the trains should keep you running.

Have fun and let me know if you found a defective track piece.

I had that same issue,I used a scotch brite pad to clean it and after that it worked great.