Strange that nobody has mentioned Centre of Gravity. I recently looked at 4 flying school R22s where two pilots, each of whose weight was within the seat limit, and with a fuel load to put the aircraft even comfortably below the MAUW limit, were nevertheless outside the forward CG limit.
Have you checked your R22 CG calculations?
Incidentally, these aircraft had not all been weighed by the same organsiation at the same time, so there is some possibility that this state of affairs is prevalent.
Makes you think. Flying out of CG could really make your eyes water.