I have a 2016 200hp Optimax and I have the vesselview. Couple of things...
I regularly get the 4 beeps at idle. I have checked it on the vesselview and it is (on mine anyway) a low temp warning. I ran it on with vesselview turned on and could watch the temperature. The thermostats (there are 2 thermostats on mine) are set to open at 130 but 130 is where you get the low temp warning. Temperature would rise to about 135, thermostats would open, temperature would drop to 125 and I would get the warning beeps. It would keep going like this but once running, no more beeps.
On mine, there is no float in the on-engine oil tank. There is a sensor that will beep with low oil and eventually put the motor into guardian mode. This happened to me and the issue was the strainer in the remote tank was plugged. Just pull it, wash it in carb cleaner and replace. I googled it at the time and and talked to Mercury but there was nothing on the strainer plugging. However, if you google it today there are quite a few posts with the suggestion that the Optimax oil is sitting on shelves longer because newer motors are 4-stroke.
I have only used Optimax oil in the black 1 gal bottle since new & for what it is worth, my optimax oil is and always has been brown.
And if you do mess with the oil system, make sure you bleed it properly and re-set the motor to "break-in" mode.
From Bass Boat Central:
How to BLEED the ENGINE MOUNTED OIL TANK
1. Ensure that the BOAT tank has adequate oil in it (1/3 or higher level).
2. Verify all caps on the BOAT tank are TIGHT, and o-rings are in place under the caps.
3. Remove engine cowling, and set engine trim to "level-trim".
4. If you've OPENED any part of the oil system, or suspect air may be trapped in the lines, utilize a Turkey Baster or Syringe to "suck" some oil out of the ENGINE mounted tank (usually want the level down about 3/4" to 1" FROM THE TOP OF TANK for best results).
5. With cooling water supplied to engine, start engine and allow it to idle.
6. Loosen the cap on the ENGINE MOUNTED oil tank (approximately 1-1/2 turns). Allow the engine to continue idling, and watch carefully for the oil level to rise. This is a "pressure fed" system, so oil is being "pushed in" as air is being "released" through the cap. This may take only seconds, or as long as a couple minutes.
7. As soon as oil begins to "spew" from the cap, snug it down (don't overtighten- it will break/crack).
8. Wipe up all spillage.
9. IF you have repeat occurrences of this problem, you will need to have the system checked for air leaks, faulty check valves, etc. (Same would be the case if the system does not bleed as above described).
From Mercury:
Priming Optimax Oil Injection Pump: (Required after replacing Oil Inlet Hose Filter)
- Connect water to the motor (for running it).
- Make sure remote oil tank is filled & caps are on tight
- Loosen the vent cap on engine mounted oil reservoir (don’t remove it – just loosen it)
- Fill the engine fuel system with fuel. Connect the fuel hose and squeeze primer bulb until it feels firm.
- Make sure “kill switch” is on (motor will run)
- Turn ignition key switch to “ON”.
- Within 10 secs move remote control handle from neutral into forward gear 3 to 5 times.
- This starts priming process which may take a few minutes (you will hear the oil pump ticking)
- Start and run the engine till oil overflows the engine mounted reservoir tank
- Turn off engine and tighten the engine mounted oil reservoir cap.
- It also resets the engine break-in period (more oil for 2 hrs of running)
Hope this helps...