[Water Warrior 2]

I doubt the stator will be burned up or damaged. Alantf can confirm this but it puts out maximum all the time so a slightly extra load will make no difference to it. I think what you are noticing is the voltage drop with the extra draw of the added lights. Most noticeable at idling speed. I wouldn't worry too much about it. The charging system will replace any power loss's to the battery once the RPM increase again.
An effective alternative would be LED lights. That can open us many possibilties if you are so inclined.