Hi all. I recently purchased a few trains in a bundle listed as "parts or repair". While the shells and details are not in the best condition, surprisingly all the mechanisms work very well. One of the locos is an Athearn 2-8-2 with the stock digitrax decoder. I ran the engine and while it ran smooth and quiet, it pulsed down the DC track. It would run a few inches, slow down a bit for an inch or two and repeat. I stripped the loco down to disengage the motor and gear from the wheels. Wheels rotate very smoothly and no cracked gears. However, even when the motor is powered directly, it still pulses. I do not run DCC, so I cannot test this any other way. My question is, can the decoder be causing the pulsing? If so, I can rewire but I didn't want to cut the wires if this isn't a possibility. Appreciate all responses.
Thanks for the response. I'll probably take the decoder out and rewire. There are no direct replacement motors that I can find, so there is nothing to lose.