Just bought engine started cold fine after 40 minutes running stalled in idle engine does run but shut down in idle

"Hi there guys,

I just boug

"Hi there guys,

I just bought a '05 Bayliner 249 with mercruiser 5.0 MPI.

Here is the problem. We started the boat at the dealership I bought it and it started perfectly. Their service dept. did a compression and mechanical test and everything checked out fine. They even shoot a video of the boat running to show it ran perfectly.

I took it out on Saturday after I picked it up and it started perfectly at the marina. Batteries were a little weak but I figured they would charge during the ride.

After like 45 minutes in the intercostals a boat in front of me slowed down and I quickly slowed down to idle. When the engine got below 1000 rpms it just stalled. The boat would turn on in neutral and very accelerated. If we brought it back to idle it would turn off again. We were able to fire it back on to get to the ramp and again arriving to the dock the boat stalled.

No wierd noises or anything. When the boat was running it was perfect. Lots of power, picked up speed fine, exhaust was warm to touch, hoses seemed ok. From reading other posts, my guess is a dirty IAC.


Any thoughts???

Thanks,"

"so you are saying that in all

"so you are saying that in all OTHER respectsthe motor runs perfect... goes fast does everything correct... just won't idle ? if so, the iac sound like the first place to look."

"yeah pretty much. This is my

"yeah pretty much. This is my first boat and I do not know too much about them. I was with a friend who has owned a few and he said that besides that, he did not notice anything worng with it. We full thottled the boat and it reached 43 miles maybe with no weid sound or overheating or anything.

It is just the issued that when slowing down to idle it will shut down."

"then just slide the iac off,

"then just slide the iac off, hook it uo to the harness and turn the ignition on it should move around some and allow you to compress it all the way and " exercise it and make sure the little cone is clean. sometimes they get sticky from sitting"

"will do.

I will also be c

"will do.

I will also be changing the fuel filter, adding stabil with ethanol treatment to the gas (since I do not know for how long was that gas in thre) and cleaning the IAC.

JP"

Update: Well it turns out that

Update: Well it turns out that the problem I was having was the IAC. It was closed shut. A little of carb cleaner and WD40 fixed the problem.