Yamaha no start ,,,start

[steplift20]

2003 115 4 stroke Yamaha , I was out Sunday ,everything was good then I went to start my engine and ,no start,just cranking, I played around with the kill switch checked the battery cables and still not starting after about 30 minutes I tried it again and she started right up and been starting ever since .i was leaning towards the kill switch but how can you check it if it starts, and what else could it be? I fish were there is channels with huge vessels and don't want to think about that not starting. I had to get another boater to pull me out of a channel and had my family with me. What do you think I should check? Any help would be appriciated . Thanks