2002 225 4-stroke cutting off

[Holton810]

I'm needing some help. I've had my boat to a dealer and they said nothing was wrong. Well, the very next trip, i didn't make it a 100 yards from the landing and it cut off. The engine will be running fine at any rpm and will cut off unexpectedly. Sometimes it will crank back up and sometimes the ignition switch is completely dead. I have noticed that when it's dead, my voltage has dropped down to 7.5 volts on the dash gauge. I have 12.4 at the battery and at the lugs on motor. What can be causing this? During this same time, i have no power to the trim function. I found that the fuse wasn't making a good connection and thought i had found the source. Well, 80 miles from home on vacation trying to enjoy time on the water with the family....and engine cuts off unexpectly again. Please, if you can help....please help with any suggestions.