lehner quark cogging

my g2r with a 1940/9 and quark 125b speed control, cogging real bad at stop if you push it it will run till you stop again then cog real bad. don't know if its the speed control or motor. we were running it pretty hard for about 15-20 min pretty much wide open, by the way it is a 5s 8000mah set up. any ideas were to start?? thanks in advance for the help.

[ClodMaxx]

did you have the BEC eliminated, either with a UBEC or receiver pack?

[BrianG]

How hot did the ESC or motor ever get? I would try a different motor or ESC, if you have a spare laying around.

i have a ubec & they both got pretty hot

[zeropointbug]

K, you might want to open up the power input end of the Quark and look inside to see if a capacitor had blown. (there are two of them)

How fast do you have to push it until it starts moving?

Don't just look to see if they are blown. Look at the tops of the caps. They should be flat. If they are puffed at all, the caps went. Frank at S&T informed me that they did have a shipment of substandard caps a little while back. You may have gotten one, I know that I did.

If it is the caps, you could just replace them yourself. They are not hard to get to.

[zeropointbug]

Yes, they should be flat at the end. Also, if the shrink wrap on them has torn, then that might be a sign that they have overheated as well, and partly damaged, and using it more will eventually kill it.

[Serum]

Might be the LVC kicking in as well. Did you removed the red wire from the esc?

I noticed when I was over geared with my Quark it would cogg, just like you describe. So you may try gearing down to see if there is any difference.