Vapor lock isn't uncommmon for boaters this time of year. I am told the Summer blend and Winter blend of fuels have different temperatures in which they turn to vapor. Likely there is still "winter" fuel in the fuel line, turning to vapor in the fuel rails on top of the warm engine. One thing you can try.... turn the key to run the elec fuel pump 2-3 times before engaging the starter. If it doesn't resolve itself after another tank of gas, then we will need to address that.
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Walt B
"Debt-Charged"Black '07 H210SS6.2L Bravo One turning a 21P HIFive
Wakeboard Tower with Perfect Pass Stargazer version
Missouri River; Kansas City, Mo.