Low oil beep Mercury optimax

I'm on the lake fishing right now and I'm getting 4 beeps every 2 minutes when my motor is running....I have a 2010 90hp optimax......I googled it and it said that it is the low oil alarm.....my tank is full! What could be the problem? Is it safe to still run it today or should I go in?

Check the oil tank under the cowling and make sure it is 100% full. You are safe to run.

The onboard tank or the tank on the motor? The alarm goes off the sensor from the tank on the engine. If it's about 1/4 low, it will beep. Fill the engine tank up (ALL the way) then make sure the cap is tight. You might also try raising the motor all the way up and then all the way down to see if maybe the float (engine tank) is just stuck. Check your oil lines from motor to boat and back to make sure they aren't pinched. If you still get alarm, take it to a shop soon. Good luck and be safe.

If the small tank under the cowling is not 100% it will go off. Oil tank sensors are known for going bad also on Mercurys. One other thing you can do is if it is NOT 100% full loosen the cap while motor is running and let the oil fill up but be sure to get the cap back on before it over flows or it will make a mess. 4 beeps every two minutes is saying don't panick but get me checked out 1 looooong beep is oh [censored]! Hope this helps

Are you sure it's not the overheating alarm? You might need a new impeller.

If it were me I would head back toward the ramp and fish close to the ramp, that way if you get the long beep, you can troll back no problem. If it's still under warranty, then run it hard and let her rip!

Tom Mayne is correct, 4 short beeps you can go several days (Not recommended). One long beep you have just ran out of time. Sensor is pretty much on top of reservoir, does not take much for it to start the beeping process.

Looking at your model (picture) sounds like the sensor is needing replaced. Shouldn't be going off until your only 1/4 tank left.

Float in the oil tank has sunk to the bottom thinking you are low on oil. Will need a new oil tank

Thank yall! I'll take it in and get it checked out!

Fill the tank up. And unplug the sensor. Should be an open contact sensor I believe. If it quits beeping then it's the sensor. Gota love the optimax.

The float in the oil tank under the cowling is off and causing the sensor to read no or low oil. Happened to me. New oil tank for under cowling around $50.

Oil pump could be going bad, that what happen to my father engine burn it up.

I'd rather mix my fuel and know it has oil. I'd take that vro tank off and plug the hose using the vro pump as my fuel pump and just mix it and be done with it that motor is to expensive to not know for sure how much oil it's getting. The vro pump went out on my dads and when it did it beeped one time and it was to late the motor was already blown up just my .2 cents

Had the same thing on my Cat, full onboard tank and motor tank, but still beeping.
Had a small hole in the oil line causing the sensor to go off.
Quick and easy fix...no problems since.

If you are trying ro prime the in motor tank, leave the cap off the tank when you start the motor and then fill

I had that going on. Noticed the oil was being used out of the upper tank on the engine. Found out the oil from lower tank was not being used so the upper tank was suppling all needed oil. Found out the lid gasket on the lower tank had become hard with age. The way it works is that the lower tank is pressured up and forces oil up to the engine. If the o-ring on the lower tank gets hard and fails to seal no oil goes up. The o-ring looked very good but it was hard and would not seal like a new soft o-ring will. Replaced the old hard looked like new o-ring problem fixed. Stopped pulling oil from the top engine tank problem solved. The top tank had a flat rubber gasket and i replaced it a few days later just because i wanted to. If a one dollar upper tank gasket makes me feel better I'm going to do it too. Just saying but been there done that.

This is a great site. So many tried to help. Awsome

Yea no doubt. The evinrude vro system sucks. However the mercury oiler is a little bit better. And this is an optimax, which can not have the oil injection deleted.

I just had this problem! Check the sensor for continuity, if it has none it's either the sensor or the there's a magnetic ring that sits on the float that activates the sensor. ive been told the sensors hardly fail. if your like me the magnet falls off the float causing your sensor to tell you it's low, and unfortunately you have to replace the on motor resivoir. I hope that makes sense and helps.

Most common is the oil tank float goes bad requiring replacing the complete oil tank. Water in the fuel or the water sensor will cause the 4 beeps also. Had a 115 Optimax doing this found it was #30 Here: http://www.boats.net/parts/search/Merc2/Mariner/90%20DFI%20%283%20CYL.%29%281.5L%29/1B736885%20%26%20Up/Vapor%20Separator/parts.html

I had the same problem. It was the float. I disconnected the alarm and kept the tank full.

I had same beeping with my 2006 optimax. found it to be the fuel filter/water separator. youtubed it and found instruction on draining the fuel line/filter. This was a quick fix but had buy the filter wrench and new filter, that solved problem.

I've had it 2 times on my 02 Opti. Both times it took an new tank like Gary stated.

its an opti cannot premix