Originally Posted by OldSoldier

OK,
I tried the suggested changes to my speed controller settings on the Quark Monster 125, but they didn't seem to help the cogging. The only setting that seemed to help was setting the Neutral range to "wide". But still there was too much cogging when transitioning from coasting to throttle...in fact the wheels would lock up momentarily when transitioning from coasting to forward throttle.

I switched out the Medusa and put in my old Feigao 9L. It was much smoother...BUT:
I ran it at 6s for about 60 seconds in a parking lot. While braking from a full-throttle run, the Quark Monster 125 caught on fire!!

I quickly removed the body and stamped out the fire trying to save my expensive batteries. I think the batteries are OK, but the ESC was a complete meltdown! I only had it for a week. I was thinking something was wrong with it ever since I got it because it never worked as well as my other two Quark ESCs.