Boat Won't Start Again After Running and/or Two Beeps Every Minute - How to Change the IAC Valve

In this video, I share my recent experience with my boat, a Tahoe 234 with the Mercruiser 350 MAG MPI Engine. The boat would start great at the beginning of the day when cold, but after running for a while, it would not start without disengaging the transmission and starting the boat in wide-open-throttle position. One of our last trips out prior to performing this fix, we experienced two beeps every minute until we returned safely to the marina. Some research on the internet led me to believe that the culprit was a faulty Idle Air Control (IAC) Valve. This simple fix was quick, easy, and fixed our problem!

Other similar engines that this fix should work on, as well, are the 5.0L and MX 6.2L MPI sterndrive engines.

Since the 350 MAG MPI Engine has been produced over a number of years, there are some variations in the engine model numbers, with respect to the necessary parts. The video attempts to detail those differences and provides the necessary OEM part numbers.

The engine on this Tahoe 234 has a model number that falls into the range of 0W650000 thru 1A299999. Parts needed for these models are as follows:

35-8M2001030 - IAC Muffler
862998 - IAC Valve

Similar engines that were produced previous to mine, falling into the range of 0M300000 thru 0W6499999, would need the following parts:

35-863829 - IAC Muffler
862998 - IAC Valve
27-8M0119616 - IAC Gasket

I am not a licensed mechanic and do not pretend to be. I'm just a fellow boat-owner trying to share my experience and hopefully save you a little cash. Anything that you do to your boat is your responsibility and, as always, if you're not comfortable doing this, consult with a real mechanic.

Please feel free to share your thoughts and ideas in the comments!