Well...a lot of it depends on the batch of motors you get. I've NEVER broke them in. Some last two days, some last over a month. I know I should "break them in". Causes more normal and even wear to the guts and makes everything work smoother together, and reduces friction and excess heat build up. But being how I never break them in...I know a weak motor from a good one within a few days. Yeah...I can be a MORON if I work at it.
ORIGINAL: rcmiket
The motor I burned up in about 8 minutes time had the polarity stamped on the plastic case. I didn't break it in (my mistake) but 8 minutes that's insane. I ordered 2 more replacements which I'll break in we'll see how it goes. Meanwhile I put the stock system back on have been playing all day with no mishaps. (yet) ..........