Smoke & Sound

[C.McLean]

OK, 25 to 30 years ago, I visited "The Train Shop" in San Dimas California. It became one of my favorite places to go as a kid. Around 15 years ago, I went back and saw these Big Trains running overhead. I said I will have one of these someday.
I just bought the Bachmann Liberty Bell, from a seller on Ebay. It came without smoke fluid. I have had the train set up for about a week now, and it has run without the smoke switch on. I just recieved the smoke fluid today and dropped about 12 drops in(the directions on the bottle call for 20). The directions in the Big Hauler call for 4 or 5. Running the train now, I get a very small "wiff" of smoke every 5 or 10 feet. Is this normal?
Also, the train shuts down after 15 minutes of running with the smoke switch on.

Colin McLean
Fort Mohave, AZ