Dealt 611trouble

i have a dealt 611 in my x-carve and it has been working good till just now it will speed up then slow down i have only done two small jobs on it and i do not have it ran threw my x-carve did i get a bad 611 or is it some thing i am doing wrong

hmmm so the rpm increases and decreases randomly?

I would say you got a bad router for sure I would have them send you a new one

Sounds like bad brushes, usually caused by running too fast for too long. Replacement brushes are cheap.