My Formula has a timer on the alarm, so you have to leave the key on for a little bit before the timer ends and the horn will sound. Its good so you don't hear it when your starting, but bad usually won't know if its not working. Should say it use to turn on, but has not since repower, I still have to fix that

run the boat on a remote fuel supply tank with new fuel line attached and current fresh gas. just to eliminate all the boat side fuel systems. These kind of testing helps narrow down where the problem(s) are

BUP - mine is definitely an electrical issue. It has fresh gas in it as I have been filling the tanks for testing. I've been working with a tuner. I have the MEFI burn software. He sends me the file and I upload and try it.
The boat cutting out is recent. As mentioned earlier it starts right back up. No fuel starvation at all. Filters are all new this season. After it cut of the for the 3rd time, I restarted and ran at various rpms for over an hour without cutting off.

As a tech tip; even if not the problem I would take the msd coil out of the loop. These things are less reliable than, say, a 1986 Hyundai Excel.:(

Look up ratings of your exact coil (assuing #8226 ?) at Summit Racing and amazon,, many people had problems soon and some within days. remember, MSD no stands for "My Spark Dies."

=============

Typical module and coil issues show up hen hot, then okay for a little while when cool. Then get weak when hot and/or not allow restart until cools backdown. However, past dozen years or so, MSD anythings have caused normal and not not normal issues.

=================

Tell us more about your fuel pump and wiring issues before 'your fix."

did it ever do it before the coil change ? I had the same coils on a pair of carb engines and they would over heat the timing module to the point it was double firing @ 10* and 270*.......put the stock mercury coils on and they ran perfect, Id try the stock HEI mercury coil. BTY they are for sale cheap.......:D

SB/Baha Rooster/ F2 speedy - I have a stock coil for backup. I will try that first. Ignition module comes to mind as well. I might go ahead and replace that.

I have an Automotive 1000 marine pump. My only issue with that was the circuit. I found this by checking all the wires and it ended up being a bad connected from the blade connector to the fuse block.
I replaced the entire fuse block (blueseasystems) and no more issues. All are screw style vs blade connections. They are all secure.

I changed the ignition coil back to my stock coil last night. Had to change plugs as well. Ign module will be in Thursday so I will replace that as well.
I started and ran it for a few minutes in the driveway. All seems good. I won't know for sure until I water test it later this week.

Hey 99 the ign module is a good bet but if that does not fix it, give me a call. Too long of an explanation to post but easy 5 min diagnostic.

Chris

727-599-1941