Primer bulb leaking down

[BASSBOAT21]

2000 johnson 225 ho---relaced bulb with johnson original one---replace gas tank inlet valve---heres what it does---cranks ,runs fine no cutting back or anything--no backfires---run to get to place where u are gonna fish shut off enginelet it sit for couple hours or so go to crank back up --it cranks up but put in gear and throlle up to go --cuts off---u have to go to primer bulb reprime hard and u will take off and go just fine--all lines are no leaks--lines to intake clean and freely flowing--this is a carb engine with gas and oil mixer attached----any ideas--this only happens as stated none of the other time just dam aggrevating to have to reprime every time it sits for a while--

[boats.net]

May be vapor locking, try idling engine for a couple of minutes before shutting off to cool engine down as much as possible.