You may remember I had a breakdown on one of my FEF units. The motor needed a nudge on the flywheel to start rotating. Once it rolled over all was good until you stopped. Then it would not restart rotating. I went ahead and bought a new motor from Kato and last night put it all back together. Unbelievably it took right off with no adjustment of the Soundtraxx Decoder. It runs smoother now than ever before and the Decoder has none of the jack rabbit starting that they had with the 1st run. It is perfect. It will creep tie to tie set on 128 speed steps at setting 1. Never did that before. I don't know if Kato modified the coreless motor but it is 100% better than ever before. I don't know if they actually changed the motor characteristics but I like the results of the new motor.
I may have spoken too soon... The decoder and loco run perfect on 98% of my layout (it's 12 years old and track work was great) but now that I have totally disassembled and reassembled this loco, I have 1 spot on the layout and all places it is under a hill in a curve with super elevated track. Don't know why yet but the lead set of drivers lifts at a joint and comes out of the tunnel off the track. It has to be the loco because I have 2 more just like it that run the entire layout flawlessly. Tonight the 844 goes back to the roundhouse.
Turned out to be my fault. Was tinkering around with a combination of a curve in a tunnel transitioning into an incline. Not a good combination of events especially with Unitrack. Never had issues when it was all flextrack. There were no joints to contend with or super elevation. All my joints were soldered. It runs just fine with diesels. Only 1 of i out of 30 locos acted up. Regardless, all is well tonight. I may start relacing some of the unitrack with flex and roadbed to knockdown some of the joints. We shall see.
It sounds like your first motor was defective. Despite Kato's outstanding design, fabrication and assembly quality; with motors they are at the mercy of a supplier. Fortunately, replacement motors are readily available and easy to install in most locomotives.
I went too far taking the mechanism down to diagnose the problem but I wanted to know it wasn't a piece of tree material or ballast, etc that was caught up in the mechanism. The motor replacement is really straight forward and quick. It is doing well now.
