I have a 1997 Celebrity I/O with a 205 ford engine. After we run around the lake for thirty minutes or so and turn off the engine to let someone tube, it will not start or be incrediably hard to start. I have had it in the shop, twice for the problem and they keep telling me that older boats like this are finicky and not to worry. I have had to be towed in twice because it will not start. First start up of the day is easy in nuetral and even after I give it gas it will either not start or take several cranks. Any suggestions will be great. It had a new fuel pump a month ago and the choke has been checked and is operating normally.