Reply to "Sparks and Reduced Power in Insulated Track Section"

Thanks much for the replies and suggestions.  Yes, am using tubular track with insulated outside rail with fiber pins and the heavy old Lionel cardboard material around the rail at the ties.  The insulated section is two straight lengths of track.  By nothing connected, do you mean disconnecting the accessories and then running the train through the section?  I can try that as well as disconnecting all of the accessories and adding them back in one at a time.  I can also check with Ohm meter; haven't done that yet.  All of the accessories are powered from the "D" fixed voltage terminal on the KW.  The locomotive makes it through the insulated section with only a slight slowdown, but the sparks are clearly evident.