Wendy Before you go changing settings on your machine such as hook timing check the Under Thread Pressor (PN#10184-01) , it is mounted under the fixed knife which is located under the needle plate. The Under Thread Pressor (UTP) may be slightly bent causing it to rub on the back side of the rotary hook. As the machine starts to sew you would hearing a clicking sound that would steadily increase in frequency as the machine speeds up. it is almost always not an issue. You can check this by removing your needle plate and then going to the maintenance menu / head timing menu, and clicking on Head up as you watch the UTP as the hook rotates. If those two parts are making contact chances are this is where your noise is coming from. It would probably be best to call MELCO and order a new UTP. Again its not an issue that would affect the way the machine sews. If this is not it I would still not jump in and make adjustments to the rotary hook. Remember that you have 16 needles on this machine, one adjustment to fix one issue could create others. Hugo Torbidoni