Why would you buy 2 sidewinders?

1 Mamba Monster setup is about the same price as 2 sidewinder systems... And a LOT more power and way less headache.

Also, part of the problem may be that you need to prevent one ESC from providing power to the receiver. Try de-pinning the red wire to the receiver on one of the ESCs. You don't want both ESCs trying to power the receiver at the same time. It can cause issues.

-Eric