7 year old batteries no doubt YOU NEED BATTERIES. Your lucky they have not stranded you. ECM/ PCM controlled engines need steady and the correct voltage to receive the proper inputs from the 5 v and 12 v reference sensors and signals to command the proper outputs from the computer. It all starts with battery voltage as soon as you turn the key on.

Also I was asking if you change your perko selector switch while the engine is running not after the engine is shut down or before start up. I understand turning the perko switch off when your done using the boat.

Also is your stereo hard wired straight to the battery still drawing power/ amps when the perko switch is turned off. See this a lot and the batteries going dead weeks later after the boat sits .

7 yrs ?
WOW !!!!

BTW: A dead/shorted cell battery will pull a 'good' battery down with it when they are connected.

I suggest using 'all' only for jumping a battery.

2 beeps every minute could be IAC - 4 sure. Solid beep at full throttle could be overheat and or exhaust manifold temp overheat. This also could be throwing the engine into limited power reduction mode. (guardian mode) from 5 % to 90 % available power depending on what the problem is.

Also solid beep can be overspeed / (over reving) bumping off the rev limiter. Hence this also can put the engine into 90 % available power mode or less. You need batteries 4 sure before you do anything else even for scanning the engine. Good luck

ok i will start with some batteries and a scanner and see where that gets me. I never turn the perko switch while the engine is running. The stereo does not work with the batteries off and isnt wired to them either. When i bought the boat the previous owner stated that they would draw down quick if the batteries werent turned off and that he had replaced the batteries seveal times so the batteries drawing has been an on going problem for years. one thing i did forget to mention is last time i had it scanned the crank sensor was reading -112 which is a misreading for sure but the boat ran fine for several months after. Im not sure if the pcm could be drawing these batteries down or something else.

An interesting thing with newer FI motors. It takes much less current to crank them as the small gear reducted starters are quite efficient, but much more current to run and support the electronics. An older carb motor really only needs enough current to run the module and the coil.

The point here is that you may never even here a change in cranking speed but the batteries are not even close to being up to snuff. Battery test is step one, checking terminals for tightness and cleaning step 2. Until you are sure the base electrical system is valid, I wouldn't get too crazy about what is causing the alarm to go off. Once you are sure your batteries are up to snuff you can move on to the alarms and battery draw.

And I had a battery go 12 years on my Regal. I was so amazed after 8 years that I decided to see just how long it would make it. It's easy to take that chance with 3 batteries and a push button parallel switch. When it did quit, it crapped out all at once with no warning.

Yeah I agree I definitely need to get a set of new batteries then go from there. I'd say 7years is a long time for a set of cheap autozone batteries the previous owner put in