It's kind of hard to say for sure since it was not a problem I could regularly repeat, but I think those that suggested vapor lock were right. If that was the problem, I think it must have been partly caused by ethanol in the gas because I had never had the problem before and the ambient air temperature was not as hot as what others had reported when having vapor lock. This year, I filled up with ethanol free gas when I winterized. I'll have a better idea about it in the spring when I get back out.

The problem only occurred for me after running the boat for a while and then having it sit off without the blower running. When starting again, it had the problem. I started running the blower while anchored until the air coming out had cooled somewhat and did not have the problem again. The only thing that has me unsure about vapor lock is why I never had a problem with it in the previous 6 years. The only answer I can come up with for that is that there might have been more ethanol in the gas than in previous years.