Hope someone can help with this. I have a 99 Air Nautique with GT40 EFI and apprx 350 hours. The last 5 times out the boat started fine and ran perfect. Then after stopping for around 30 minutes or longer, it restarted and ran fine for 100-200 yards at which time it seemed to lose fuel and stopped. After sitting 10-20 minutes, it would restart and be OK. I have replaced fuel filter, fuel pump relay and cleaned the anti siphon valve. The fuel pumps do come on when the problems arise but the motor will not start. Took it to local marina who said they could find nothing wrong and billed me $400! Someone please help! (by the way, I am not very mechanically inclined)