HELP - Lionel F-3 powered B unit stalling on O-72 switches

[Anonymous]

I have an ABBA set of Lionel F-3's from the 2004 catalog. Those of you familiar with this product from Lionel are aware that one of the A units and one of the B units are powered. Recently, I've noticed that the powered B unit briefly slows down or stalls for about a second when it goes over one of my MTH O-72 switches, and then it immediately speeds up really fast, as if it's trying to "hurry up and compensate" for the brief slow down (whether operating by itself or in a lashup with the powered A). At lower speeds, it is a "hit or miss" situation - sometimes it doesn't hesitate at all going through the switches, and sometimes it does. The powered A unit, however, just rolls right through the switches without hesitating, regardless of speed.

I actually just sent and received the B unit back from Lionel for warranty repairs after one of the two can motors failed. Lionel replaced the can motor, and the locmotive has run fine except on the switches.

Does anybody have any ideas? Thanks.

[MartyE]

Couple things to check...Does this unit have a pickup on each truck? If so perhaps one is disconnected and not keeping the engine powered while the other one navigates the switch plastics. It is possible that the spacing of the pichup rollers are both touching non conductive part of the switch at the same time causing it to loose power.

Just some things to check

[Roger Bielen]

Also check that all the pick-up rollers are clean. Likewise, if it seems to be the same switches check that their rails are clean.