Erratic Conventional Operation

Well, the standard first reply: when anything like this happens I clean the track, but particularly the loco's center pickups and rollers, really well.  I find that fixes 90% of the problems like this. 

I also have the RK PS2 Y6B.  Great loco - my first articulated loco many years ago now, and one I love.  Many, many hours of happiness.  It's never let me down - when it has clean wheels. 

I have an RK PS2 Y6b also.  It is my only articulated locomotive, and I like it.  I bought it used a year ago.  As I recall, when I first got the Y6b and before I got my DCS, I had notices a similar problem.  I have had trouble with DCS, and want to run it conventional.  The Y6b has been sitting a while waiting for me to replace a drive rod screw that fell out right before I had hand surgery.  I had better get it back together and try it conventional before my other hand surgery a week from Monday.  Now I want to see if I am having similar problems.

Look for a traction tire that came off the wheel and is hanging in the valve gear.  It looks to me like you are doing everything correct.

Thanks all. 

Lee - Duh! Didn't think of that. Will do so later today. 

Ran it for a bit this morning - much better but still worse than usual. 

I recently had a similar problem. Every time I hit the whistle the train would want to pause briefly. Finally I narrowed it down to the transformer as this did not happen with others or while on another line.

 Then I hooked the transformer to another line which has a block signal hooked up directly to the track. This is when I noticed that the lights in it would black out when this happen. 

 So the end result was that I determined that the transformer brick has some kind of issue. This one was the Z-750. Removed it from service and all is now well.

 So I suggest hooking up a bulb to your line and see if you experience  the same results.

2 engines doing the same thing would have me looking at the track or transformer. ( loose wire or joint someplace) 

Hope it's not a dirty timing tape issue, not a hard fix but you do have to take the engine apart.... Maybe  try another transformer.

I seem to recall having this problem with my PS2 Imperial Hiawatha. I believe it was a lack of grease in the gear box that caused the problem. Not sure, but I tried all the other fixes and it wasn't until I lubed the engine that the problem was corrected. Always seemed like a weird fix to me, but once it started working correctly there was no need to investigate further.

Per subwayrunner's thought:

As you have multiple transformers, swap a couple loop to loop and see if

the problem follows the power source. Leave the locos where they are and run them

with each other's bricks. May not be the loco(s).

All - thanks for the tips. Sorry for being MIA recently. Will have time tomorrow to swap transformers and see what happens. Will report back. Thanks again. 

I didn't forget about this thread. 

Cleaned the wheels, track, and rollers with alcohol. 

Swapped transformers/controllers. No change really. 

Ran it on another loop that is much smaller and it wasn't as bad but very similar. Track on this loop is 1 week old and really not used yet. 

I tried another PS2 steamer, circa 2006 but had the guts replaced 3 or 4 years ago and it responded far better. Didn't try anything else but may do so tomorrow. Regardless, it appears this engine is EXTREMELY sensitive to DC off sets but why it speeds or slows so dramatically (especially slowing substantially with an INCREASE in voltage) is beyond me... Anyone have anything else to look at or should it go to a repair guy for evaluation?

No other suggestions? See post directly above this one. 

Do the rollers have signs of wear and pitting discoloration?  Cleaning rollers also requires internal.  Sometimes they just need to be replaced despite not physically grooved.

I would also open the tender and make sure the plugs fully seated especially the 5 pin motor plug.

The other issue can be the speaker going bad.  Turn volume down and retest.  If train runs fine with low volume or off (speaker not vibrating), I would try changing the speaker.

The issue maybe that the sound generation (a high demand on the 5V power supply that runs all the microchips) is effecting how the motor fet controls speed or the tach reads speed.

G