captain;s exhaust not working
 

So, I had a situation and i need your help or knowledge in figuring out why the boat didn't want to start back up after 20 min ride.
i had made modiification with zip ties for captain exhaust being open at all times in engine compartment. i went out for a ride . then turned off the engine , and with choppy waves, i ve noticed that water would drain in the captain exhaust pipes. So im trying to understand if it could be the issue where water went inside where it s not supposed to.
please help.
P.S.
after an hour drifting down, i was able to park by someone's house and after a 1st try i got a good neighboor that helpmed me with a jump of a battery. although- my battery was healthy after i got it on the trailer at the house. Turned on with a half of a second.

Re: captain;s exhaust not working
 

7.4 MPI motor?

Re: captain;s exhaust not working
 

Mercruiser 8.2l 502 mag mpi 415

Re: captain;s exhaust not working
 

Super common problem with that era of MPI big block V8s. Read over THIS and see if it helps with anything. Particularly "Situation" number 3 and "Conditions" number 7.

Being in Florida(?) You should be about to get ethanol free fuel. You should try that. Ethanol boils at 172 and these motors have a thermostat at 175... the ethanol boils in the fuel rail near the intake after running the motor and shutting it off without cooling.