I'm going to give the black electrical tape tip a try.
Loco seems to navigate the O36 curve/switch combo perfectly on the end of the layout that is level. Going from a straight and turning into a switch works fine on both ends of the layout, but it's that one area where the layout is warped and the curve is going slightly up into a straight that I get the big spark. The loco does have 6 wheel trucks (2 plastic wheels per truck) and does hang out on the curve as described by Ace, but so long as the track is flat the tight curve itself doesn't seem to be the problem.
In the fall we'll be moving the layout to a bigger room and make it more permanent being careful to level everything. Definitely will consider using wider turns on one of the loops to lessen the likelihood of this being a problem going forward.
Being one who just puts the train on the track and hits "go" I'm not sure what in spec means for the FT switch or MTH wheelset? Haven't tested the current either although I will admit to buying a voltmeter at Home Depot after reading something about dead spots on FT 10" straights from time to time. Would I be looking for a drop in voltage by doing this test? Or what should I be looking for is the better question?
Thanks for all the help!
