ORIGINAL: bigger the better
So, your saying you used the RedNeck and the stock filter and that caused your engine to overheat? FG's offroad filter has no air inlets except the ones in the rear would that not do the same?
theres no way that is what damaged your motor! only thing mixture wise is running lean. restricting air flow makes mixture rich.
if it restricted it to a detremental level it would just stall same as applying the choke. have you removed the motors plasatic cover and emptied out all the debris that collects around the cylinder? that is morte likely to cause overheating.
regards,
paul.