I have a 1998 Mariner 150 I was cruising at about 35mph and all of a sudden it seemed as if I was in neutral. Stopped the boat and shifted back into forward and gears engaged. Idled for a few yards but when I gave it more gas back to neutral. Reverse works fine, engine sounds great, no grinding in the foot. I talked to a friend and he mentioned a rubber sleeve in the hub of the prop, (Quicksilver Prop), may have broken. Anybody with some advice??