Hi Guys , So this weekend my buddy decided to drop is boat in the water for the first time this year. Avanti 22 with a 2006 383 Mpi Merc. I don't know much about those engines and their warning system but basically the boat run's ok for a minute or two and then run's a little rough and quits at the same time the buzzer goes .... Litteraly when you hear the buzzer with the motor idling the motor cut's out and drops rpm's and dies ...Even if fast idling , the second that buzzer goes off the motor drops rpm's ... it's somtimes hard to fire back up after quitting so I am thinking fuel pump , but this motor has 2 of them. How would I go about testing the pressure ?

Things we checked , Drive oil lever : good ( operating range and slightly above ) Raw Water pump : New impeller , T-stat : new , oil level : good and 40 psi @ idle ...

Any idea would be greatly appreciated

This is the motor

Thanks for the post Marc ! Oil levels are good, water pressure is good, engine oil pressure is good.

I changed the fuel filter when winterizing the boat and the boat was 50% full of gaz and we put stabilizer in it. I filled up the gaz to 100% this weekend. Dont know if the fuel filters (I have 2) could be clogged that fast ?

I have these 2 pumps on my engine:
-fuel pump:
http://www.boats.net/parts/search/Me...ler/parts.html

-fuel boost pump:
http://www.boats.net/parts/search/Me...%29/parts.html

Change the fuel filter/sep. again maybe...

^ Thanks , I think it's the first thing he will do but we will also try and grab a fuel pressur test kits form one of our friends and see how much pressure at the rails we are dealing with.

Honestly... Im kinda having the same issue...
Yesterday the wife and I took the boat on the lake for the first time this year... I had about 1/4 of gas from last year and topped it off with another 1/2 tank of 93. Changed the fuel separator and left the old plugs from last year in... figure I would change them after the first tank of gas.

SO... it idles just fine in neutral... in gear it will bog down and die, unless i give it some throttle to bring the rpms up. So basically it struggles to idle in gear. Everything was dialed at the end of last year...

At idle the fuel pressure gauge at the carb is 3.5/4.5 psi. Getting on plane the first time there was a few misfires but after that there was no issues getting on plane. Ran fine.

Im just gonna start with the basics...dump old and add new fuel... another water sep. and change the plugs. Go from there.

Woulld that motor store a fault code that can be scanned??

I think it does store codes , I will have to see who has a tool close by that won't charge the price of the scan tool just to scan it...

Your 383 should have ECM 555 in which is the same as the all the rest small blocks and V-6 models from 2001 and up until the CAT engines enter the market place.

Is the alarm solid or is beep beep pause beep beep

IMO I think you are saying solid - if so water pressure low - impeller was changed but if you have a bravo app then a very close inspection of the GEN VII waterpump impeller housing for scaring - any scaring hurts water flow and volume. Also your water pressure sensor could be bad. Again solid horn going off. It would be wise to have the engine scanned beforehand - look for fault codes and look into history and available power from the scan.

Rough running could also be the IAC - they are problem child for x amount reasons - some reason are because boat owners fault for lack of PROPER maintenance and other reason are because they are not reliable and fail.

Do you have Bravo one or a Bravo 3 or an alpha outdrive ?

Its only one solid beep like whenwe turn ignition key to on. The engine starts and run for a few second only then a solid beep then the engine stall

Its a 2006 Bravo 1 outdrive... I also have a oil outdrive level bowl mounted on the engine and level is right on the spot

I also would check IAC. I've had to replace a couple on my 6.2 MPI's over the years.

BUP - What maintenance are you speaking of that can affect IAC life? Is it replacing the small muffler/filter located in the throttle body? Thanks.