RZ2 Help Needed

[tnvolgrad]

Hoping someone can give me some insight around an issue I had today. First time launching our boat this year, let it warm up/made sure it got up to 160 and came back down, and drove it over to my dock. Probably about 15 minutes of the engine running with no issues, no weird noises, sputtering, etc - ran like a champ. As I tied the boat up the engine alarm went off and I immediately turned the key off. Turned all the power off and back on with a check engine light and then absolutely nothing when you turn the key to crank the boat nothing (no clicking or anything like that just dead) - the check engine light flashes 1 time and stays on. Batteries and everything work fine as I thought it was a dead battery or something.- all the lights, blower, radio all are on and working.

i did check the temp after I turned the boat off and it was 150 Ish. Anyone have any clue what to even look for? I did check fuses and such that I could find but the check engine warning is what I am concerned about (eg would not imagine a bad ignition switch would cause a check engine). Weird that it simply will not even turn over or attempt to crank just a dead ignition with a check engine light.

boat is a 2012 RZ2 with 300 hours.

[Wagonhound]

I think my RZ2 (MPI 340) did something similar, the cranking battery was just low enough that it wasn't running correctly even though the alternator was working. I would start by checking the volts at the isolator, the alternator, and the battery when it's running. The fact that is was running fine prior to bringing it out of storage eliminates anything too complicated.