I'm posting this for a friend. He has a 9.9 Merc, about 10-12 years old, that will die down to about 1/2 throttle from the wide open position. He must bring the motor back to idle and then start again. The problem is intermittent and can happen on the first throttle up of the day or the last one, but it usually occurs at least once during each time out. <br /><br />This started last year, so he had a certified Merc mechanic replace everything in the fuel <br />system with new components - carb (not rebuild), tank (plastic type), filter, etc., etc. In addition, he did a complete check of the motor and did a tune up too. <br /><br />It ran great for a few times out last year and now this year, it started again. Any ideas what could be wrong? <br /><br />Thanks,<br />Jim