First off, I want to thank everyone who has chimed in today; I appreciate the interest.
My thoughts on re-opening this discussion was based on:
1. My newest acquisition (the 300) does not have a smoke unit so I thought maybe that, in and of itself, is why my DC unit was able to run it, and not my other Flyer steam engines.
2. Since my 310 (which also does not have the smoker, but would throw the breaker) made me think that perhaps it just wasn't an efficient a runner as the 300. I based this theory on the fact that the 300 does run a bit smoother and quieter than the 310...
3. One last thing: when I started this thread, I was using original Flyer track; am now using Gargraves. I'm seeing almost no sparking from the tender wheels, and my lighted cabooses don't flicker hardly at all. Could there be a connection between the track conductivity and current draw (if that's the correct term)?
4. In any case (as I stated earlier) everything runs great off my 15B, so it makes all this somewhat moot; again, I was just wondering.
5. I promise I'll never bring up this subject ever again! 
Mark in Oregon
