Not sure what is going on. Went for about a 30 mile run down the ICW, from a slow troll too wide open throttle. Ran great all the way, took about a 3 hour break and then tried coming back. Thats when it would start but would not run more than about 15 sec. before puttering out. Change the fuel line from tank to engine, changed fuel filter and water separator. I mix in my oil when I gas up and doing a 50/1 ration. Bulb if firm some of the time and other times it goes soft. Any suggestions. Thanks