2011 mercury 4 Stroke- Shuts down at Full Throttle

[ramariano81]

I am having a problem at the worst time as I am set to go on vacation for the next two weeks. I got a new 2011 15 HP mercury 4 stroke last year. This past winter it was winterized by the dealer. I did not disocnnect the fuel tank however and I think there was still fuel left in the motor and tank. When I first took it out in May 2012, it ran sluggish and would not go to full throttle until after running for about 2 hours. I got rid of the gas and gilled the tank halfway with premium grade fuel ( 2 gallons in a 6 gallon tank). Seemed like it got better and eveythting was back to normal. Last week however, afetr running for about 1.5 hours on and off in the back bay, I was running full throttle and it just died down and turned off as if I hit the kill switch. It would start while choked and would run, but when I removed the choke it would then turn off again. I anchored up and after disconnecting and reconnecting fuel lines, I got it to start and went in with no problems. Yetserday, I was in the same spot and the same thing happened. I did the same thing and it started again as If nothing was wrong. About 5 minutes later, it shut down again while going full throttle. After that, I restarted and was fine going back in to my dock. I know there was gas from last summer left in there over the winter, but shouldnt that have all run through by now? I have filled it with higher grade twice. I also added another 2 gallon of premium before my last trip and topped off the 4 stroke oil recently. Besides going to the marina and losing the rest of my season. What else could be my problem. It frustrating because this motor is hardly a year old. Thanks guys. Please email me your responses if you can. ramariano81@gmail.com