Jim:
  Thanks for your suggestions regarding cutting whatever else looks like a capacitor. There seem to be two others on the PC board, blue with a red stripe I believe.  But after sending my first e-mail. I ran the engine for long enough where the problem should have surfaced again but now it ran just fine??   Maybe it was dirty wheels and a little more running cleared that up.

Anyway, I should have used the term "overspeed" when referring to what it was doing.  This is a common symptom with Bachmann steam after installing decoders.  Here is a link to more info about overspeed problems.

http://www.gatewaynmra.org/dcc/engines/bach-280.htm

john

I've started to test run my HO Climax purchased a few yrs ago.  I operate with Digitrax equipment and have installed a Digitrax decoder.  I am aware of the need to clip a lead to the one yellow capacitor, to stop the run-on when the throttle is closed.  I've done this with several other Spectrum steamers and it solved the problem, but not with the Climax.  I'm still having the run on issue.  Is there another capacitor that needs to be cut? 

Good news to report.  I had a Digitrax DZ143 decoder on hand and tried it in the 4-4-0.  Problem solved.  No more jerky operation and somewhat better low speed control.  I also have a just purchased Bachmann Chinese Mike with similar jerky operation and I will try a Digitrax or maybe TCS decoder to see if it will run better.
Thanks for the suggestions to try a different decoder.

john

I've had one of the 4-4-0's for a few years that came with DCC on board but no sound. 
I've never been satisfied with how it runs, especially in reverse.  I'm in the early stages of a new layout but have enough track down to have given it a good break in.
Out of the box, it needed speed step 10 to 12 to start moving. Some changes with CV2 and break in has helped that issue.  But still the jerkiness, especially in reverse.
I was at the National Train Show in Milwaukee on Friday and discussed this with one of the Bachmann staff.  The first thing he asked was what DCC system I was using.  I'm running with the Digitrax Empire Builder.  He said that was the problem...something about Digitrax that can cause the problem I'm having.

He suggested to try running it on DC and see if I still saw the problem with jerkiness.  Hadn't tried this before but he was right. On DC, it starts smoothly in both directions and no "jerkiness" while running in either direction.

Does anyone have a suggestion as to what I can do now?  Is this the downside of running with 128 speed steps? 

john

PN:
    Yes, I did cut the yellow capacitor on the PC board.  And I agree, this is a great looking engine.  Everything looks "right", no parts cause you to say, "they should have done it this way....."  in particular, I mean the paint, added detail, etc.. 

   I want to play with the CV's and eventually double head the Ten Wheeler with my Richmond 4-4-0, another stunning model.

   I think I've read that the Bachmann decoders don't have as many CV's but I've not been able to find a reference at the Bachmann site covering this.  Do you know where to look?

john
 

Bob:
    Having a senior moment...meant to say "8 pin" plug...

Pacific Northern:
    It's the low drivered version so the tender has less room.  Since my first post, I went ahead and removed some of the plastic supporting the coal load (underside) and it now fits.

Thanks to both of you for responding.

john

Bob:
   It's not the decoder that's causing the the problem but rather the 6 pin plug.  When plugged into the socket on the board, the tender shell is hitting the top of the plug.  There is about 2" of lead off the plug so I can position the decoder where needed.

john

I've just tried a Digitrax DZ125PS motor docoder in my Ten Wheeler.  Runs great but it would take some cutting or rebuilding under the tender shell to get it to fit.
It looks like some of you have used the TCS MC-2 decoder in this engine.  Just wanted confirmation that this one will fit without modification.  If not, I'll work at it till the Digitrax decoder fits.
Thanks

john

Taking everyone's suggestions, I started with the driver quartering. This appeared to be ok, at least visually since I don't have a quartering jig.  Looking at the brake rigging, this may have been the problem as one brake shoe may have been brushing against one of the drivers. I used a little force to pry it away from the driver.  Also removed the bottom retainer and checked the drive gear and worm for a burr but didn't see anything.  Everything appeared to be lubricated appropriately.  With the piston rods disconnected, I ran it upside down and the binding seemed to be gone (in reverse).  Put it back together and now it runs fine in both directions. 
Thanks to all for the suggestions.

John

Just purchased one of the Spectrum Richmond 4-4-0's.  It runs fine forward but in reverse, almost comes to a complete stop with each driver rotation, at a moderate throttle setting (on DC).  I realize this may clear up after a period of break in running but this seems extreme.  Several other Spectrum steam engines I own had some binding when new but this cleared up in time.
Has anyone else found this with the 4-4-0's?  And if so, did it clear up or were you able to figure out the problem?  I'd rather try fixing it than send it back.

John S.