Gerald, Usually outboards have a rocker switch on the side of the motor so you can raise and lower it at the motor instead of having to do it at the helm. If you don't have one, that eliminates that possibility. It's an UP/DOWN button found usually on the starboard side, but I've seen them on the port side on Yammies. Mine was easy to access just by taking the cowling off and looking down just inside lower engine cover. I clipped the wires and put electrical tape on the leads until I could fix it properly.
These switches are vulnerable to corrosion due to their location. Saltwater is not good for electrical stuff
I hope that helps. If this isn't the cause, then it could be the switch at the helm or another problem at another location. It's worth a check as it is a common problem.
CAVEAT: I'm not a mechanic or an electrician. I make stuff up as I go along and I apply common sense where my knowledge is ridiculously lacking. I usually figure it out, but not always. Sometimes I screw things up so bad, I have to pay someone to clean up my mess.