I have 2 Kobalt routers and they both suffered from the surging issue. The one on my LowRider hasn’t been too bad lately but noticed it again on a recent project. I did some googling and saw some mention that the speed adjustment slider may use a potentiometer and it could be an issue with the contacts on it. So, I tried it on my main Kobalt to move the slider quite a bit to hopefully clean off the contacts. It seemed to work so I tried it on my spare. It seems to also work there. We’ll have to see if this is a permanent fix but it seems promising.
Here’s a video on my spare where you can see the issue initially, then I try my fix, and it then stops surging.
