BLI F7a interesting problem.

[djconway]

I picked up my BLI F7a the other day and have been tuning its performance.
What I am noticing is that when running on 1% to 3% (Digitrax DT400 on a Super Chief system) the loco will spool up then start to move.  However it is a jump/stop/jump/stop kind of movement (not smooth at all) until it gets to about 5% throttle.
This is the only one of my BLI locos that display this jerky start and stop.
I'm thinking that the problem is in the BEMF settings, any ideas what to adjust and how much? 
The loco runs smooth as silk once it gets up to about 4-5 smph.

[Cajonpassfan]

I just sent back my new NW2 and got a replacement, no questions asked. It was acting up exactly as you describe (and my other one is silky smooth). It may well be a BEMF tweaking issue, but I turned the BEMF off just to see how the engine ran without electronic help, and it was a dog at slow speeds. Before messing with BEMF settings, I would try to turn it off altogether to test it. CV10=0 turns BEMF off, CV10=1 turns it back on. The settings may help, but can’t fix an underlying mechanical problem if there is one.
My two cents worth. Good luck.
Otto K.

[haasmarc]

I have a few BLI F's that exhibit the same jerkiness at low speed (first moving speed step) but run very smoothly at the next step.  If anyone finds an answer I would really like to know.