[tdicamillo]

I bought a 1999 Z222 Shaba 7.4MPI the end of last summer and the family is loving it. The last couple of trips out I have been struggling with random beeping alarm. It has the same tone as the 2 ignition beeps at key on. It's sporadic only coming on for about 5 - 30 seconds solid (no beeps) and then all is quiet again. I have read most of the forums posted here and from what I have read that alarm only comes on with 3 conditions - Temp, Oil Pressure, and out drive oil low. My temp is about 120 and oil pressure gauge at 40psi most of the outing. I originally thought it was the out drive oil, so without having the history of the boat I thought it be best to start out there. Changed the out drive oil and next trip out same thing. The next thing I tried was disconnecting the out drive oil sensor since I read it is an open circuit if full. Thinking maybe the sensor was bad. Next trip out same beeping.
I found another thread about the MEFI codes and using an LED to read them. (Thanks Hudson River Steve) The engine is all clear no codes but the 12 code(one flash, pause, two flashes - Self Diag system normal) when I entered service mode. During the next trip out the water was calm and did notice a misfire when running. Is it possible the beep is sensing a misfire and not placing in a code I thought? She has 350hrs on the motor, next step Cap, Rotor, and Plugs. Upon pulling the cap and rotor I was surprised to find the top of the rotor rubbing on the inside of the cap and the center carbon button melted into the top. (See pics) These pics were taken after messing with it for a couple of days so some of the buildup came off and the carbon button actually popped back out when my son was messing with it. The rotor is keyed with the distrib shaft and I found a piece of plastic stuck in the key channel. I can only assume 2 changes ago a piece of plastic key broke off was left in and the new rotor they installed didn’t seat all the way down. The one I pulled out had the entire key intact. Hopefully this is it. We go out again in two days.

The only other thing that I know beeps is the built in alarm on the depth finder, which was off the entire time.I have 2 batteries on-board and have not had any issues starting it.

[Motoxxx43]

I had a bout of random beeping on mine at some point in time when I first got the boat. I think I replaced the gear oil reservoir and it did nothing. So the next thing was the temp sensor. If I recall correctly there are two temp sensors. One tells the gauge what to display and one tells the computer "too hot". It was like a 26$ part and it fixed the issue. Both of these sensors are near the thermostat I just cant remember which sensor is which. Unplugging one and watching the temp gauge to see if it goes to 0 could prob get you in the right direction.
Mine is a 2000 7.4 MPI, I think they are the same.

[Motoxxx43]

How many hours do you think you have on that distributor?

Just re read your issue and noted the 120* temp. I believe these boats like to run aroun 170-175. There may be something to that, I dont know.

[tdicamillo]

Thanks Motoxxx43 I didn't realize there are two temp sensors. I will look in that direction next.

As for the age of the distributor I have no idea. I just bought the boat end of last season. I put in the new cap and rotor and do not see any wearing like the pics I posted. I think that broken plastic part of the key was preventing the rotor from properly seating all the way. After installing the new ones I cranked over then engine and removed it for inspection and didn't have signs of rubbing.

[Motoxxx43]

I went an looked at my 7.4. There is only one sensor. I don't know why I was thinking two. But I did find them for around 16$. Might be a good place to start. I'm sure there is a way of testing it.
After reading some other posts the operating temp seems to be 170-180.

[tdicamillo]

FYI,

I replaced the cap, rotor, and temp sensor. After 5hrs of running over the holiday weekend no beeps!!!!! Hopefully it's fixed.