J/30 Class Association Forums J/30 Forum The Boat, Sails and Equipment Prop Vibration, Slipping Clutch??

I have the same problem with my J-30. It is not the clutch (on my boat). It is the prop not opening. Sometimes when I try to accelerate I have a big vibration but if I slow down the revolutions then open the throttle again it usually seems to open up OK. There is a fair amount of play in my prop. Of course there is always some amount of vibratuion with the J-30 engine anyway- even when the prop is competely open.