Had out yesterday 1st time this spring, fresh fuel, ran fine up to 3/4 throttle, after 15 min warmup went to full throttle- immediately died, restart was hard with a different noise while running, shut down- electric motor in to shore. tried today at landing on trailer, started easier but still sounded bad running rough, pulled plug wires 1 at a time- no real difference between the 3. also what should charging voltage be? I read 12.8 on meter @ battery @ idle.