Berk Won't Smoke Consistently

Did you check the smoke resistors?  Sounds like either one or both are opening up or there's an electronic issue.  Have you tried running it with the shell off and stopping it when it ceases producing smoke and checking the voltage across the smoke resistors?  That would tell you if it's the smoke resistors or something farther down the line.

If all else fails, you can also take the unit out and power it on the bench and run it for a spell and see if it fails.

Do what John stated and look for 8 OHMS.  Your problem should be nothing else but that if it does smoke and you know the wicking is good.

John, Marty,

Thanks for the tip. I did run the engine and tender with the shells off, but when the smoke quit working the engine was out of reach. I will try running the smoke resistors on the bench as you suggest. More to follow.

The plug to the PS2 board has four leads, two for the smoke resistors and two for the fan.  If you apply 3-4 DC volts to the fan (5 maximum) and start at round 6 volts AC on the smoke resistors, it should smoke away for as long as the fluid holds out.  That should verify if it's the smoke unit.

You shouldn't have to take it out of the locomotive, just connect to the plug with some #22 solid wire in the connector holes.

Sounds like the issue is either the resistors or perhaps something on the PCB on the smoke unit.

Note that the smoke unit has to be grounded, that's the frame return.  I had one that was loose and it stopped smoking.  Check good continuity from the wheels to the frame of the smoke unit.  One of the screws on top of the smoke unit brings ground to the PCB.  Obviously, that one should be tight.

Sorry but PS2 smoke units do not "ground" to the chassis, rails or anywhere other than the PS2 boards.  Fooling around with a DMM checking between the heaters and the rails or chassis is a real good way to destroy the boards. 

Thanks for the correction guys, I guess I've spent too much time with Lionel.