Today I was accelerating out of the Boca Raton, FL inlet in my 2600
Martinique and just as I came off about 10 knots, the motor made a loud
noise and there was a loss of power. I immediately put the throttle into
neutral but the motor kept running and everything seemed fine. I throttled
up slowly but when I got to approximately the same power level the same
thing happened. The noise was kind of like if you took two two large 2"x4"
pieces of wood and banged them together real hard. You could feel a but of
a shock in the deck of the boat. It almost sounded like an engine mount
moving or something but the motor seemed totally fine. I just had the motor
checked out, oil changed and they checked the oil in the outdrive for
water... everything was ok. About 6 months ago I had the props removed and
outdrive oil changed. The inner prop on the engine had siezed onto the
drive shaft and they had to cut off the hub and re-mill the prop... I'm not
sure if any of this might be related. The noise happened the last time I
was out in the ocean about 3 weeks ago after about 3 hrs of troll fishing
and I powered up to head back to port. Today I had just picked up the boat
from the marina after new bottom paint had been applied and the boat was
fully washed and waxed. After the second time this happened today I decided
to head back to port and plan to call a mechanic next week.

Any ideas wht this might be?
The boat is a 26ft Wellcraft Martinique with a single Volvo Penta 5.7 GS
motor and stainless DuoProp.

Thanks for any ideas you can post.
-Mike