Mercury out board mechanic question

[Jerry H]

Are there any Mercury mechanics on here?

I have a 2012 Mercury Optimax 75 HP.
Yesterday while on the water I got an alarm. 4 beeps every couple of minutes. All the info I can find in the owner’s manual and online says it is either water in the fuel or low oil.
I checked the water separator per the instructions in the manual drained it into a glass jar so I could see what came out and it was all gas.
I have checked the low oil sensor and it appears to be working correctly. Checking with a mutli meter the sensor is closed when the tank is full and open when empty.

Any suggestions on what could be setting of the alarm.
This is a new boat to me and only the 3rd time I have had it on the water.

Thanks

[texasair]

It probably the neutral shifter sensor located at the mid point on the engine.
Goes bad a lot on that vintage of Mercury's and mimic's overheating alarm

[Jerry H]

It probably the neutral shifter sensor located at the mid point on the engine.
Goes bad a lot on that vintage of Mercury's and mimic's overheating alarm

According to the book an overheating alarm is constant.
I am getting 4 beeps every couple of minutes.

[coach2]

Mine did the same thing. It was the sensor for the oil reservoir.

[Jerry H]

Mine did the same thing. It was the sensor for the oil reservoir.

I think that's my problem too but want make sure before I drop $350 for a new tank and end up with the same problem.
According to what I am seeing on the web you can't replace just the sensor you have to replace the tank.

[mechhead]

Been there...

https://youtu.be/h2fqBDjPwpU

[Jerry H]

Been there...

https://youtu.be/h2fqBDjPwpU

I watched that video earlier. What were they thinking when they chose the music for that? Good lord it is awful.

[Jerry H]

Bump for the Monday crowd.

[coach2]

I think that's my problem too but want make sure before I drop $350 for a new tank and end up with the same problem.
According to what I am seeing on the web you can't replace just the sensor you have to replace the tank.

Correct, you must replace the entire tank. I dont remember how much it was but that sounds about right. I was told it is a common problem after about 5 years old.

[Jerry H]

Correct, you must replace the entire tank. I dont remember how much it was but that sounds about right. I was told it is a common problem after about 5 years old.

Did you DIY or put it in the shop?
If DIY how did you bleed the system?
I am ordering the tank when I get home from work today.

[Oleman]

Changed the tank, added oil, and my ex 90HP was good to go.

[Jerry H]

I put in a new oil tank and that did not fix it.
After about an hour of driving I started getting the same alarm as before

[sasqy]

I put in a new oil tank and that did not fix it.
After about an hour of driving I started getting the same alarm as before

Post up on Scream and Fly !
Boat mechanics all over that sight.
Someone will answer any questions on there.

[sasqy]

Best Merc mechanic I know is The Snowman at Whitney !

[Jerry H]

Post up on Scream and Fly !
Boat mechanics all over that sight.
Someone will answer any questions on there.

Thanks I will check them out