I have a 1996 330 Sundancer with twin 7.4 V Drives. The other night my port engine was dropping out about every 5 to 10 seconds and then quickly recovering. I brought the boat in and changed the fuel filter. Same issue. I swapped the coils. Same issue. I then changed the fuel pump. The boat was running fine, however,, when I shut it down and try to start it the next day, I had no luck. I pulled off the fuel filter and noticed it was not topped off. If I top off the fuel filter and dump a little bit of fuel into the carburetor the boat will fire up and run. However when I shut it down and check hours later, it won't start and once again the fuel in the fuel separator is not topped off and below the in and out hose level. I was thinking maybe it was an anti-siphoning valve issue, however I switched the engine to the starboard tank and after shutting it down, once again the engine wouldn't start and the fuel level was low in the fuel filter. Any ideas????? Thank you!