as KMS says shouldn't be a problem, the RFM allows operation down to 920lb Gross weight and the RRPM should remain inside limits if flown within the parameters specified in the Manual.
If it looks likes its about to scurry off out of limits it may be set up wrong. The maintenance manual does specify what RRPM you should get for a given Gross weight and DA so you can calculate it from that.
However if you get to that point where you think it may go out of limits in flight might I suggest you take someone with you of great experience who knows how to read the figures and how to recover if it does go wrong.
Cheers
V.