two loud "bangs" 1989 Evinrude 88 spl

[pennyanman1]

Over the weekend I had two occurances of a loud "bang", both times going over a fairly large wake at fairly slow speed (around 3000 rpm, maybe 15 mph.) The previous week I ran this engine over 200 miles in almost 14 hours of running and never heard this sound. My buddy thinks I hit bottom, ( a possibilty given an average depth of less than 5 feet.) the boat never did it after, but the puzzle is that no paint was missing from the skeg, and the engine speed never dropped. The only other thing different is that I've installed Power trim and tilt at the start of this season. Is it possible the engine moved during the wake crossings and then returned to it origional position very quickly? I removed the tilt pin completely, so I can tuck the motor all the way in for getting a heavy load on plane. Should I still use the pin?