Oil Alarm And 1/2 Full Oil Resevoir

[riffminer]

I recently bought a used bass boat with a 2003 Mercury 200hp EFi. Serial number OT773879. While installing a fish find I discovered that the alarm had been unpluged. I pluged it back in and received a low oil alarm 4 beeps about a minute after leaving the key on. I checked the tank under the hood and it was down 2 inches. I filled it back up and I no longer get the alarm. I contacted the previous owner (who had failed to tell me about this and said he didn't unplug the alarm) and he said he had on occasion put oil in that reservoir. So there is repeated oil issue. What could be the causes of the reservoir tank not stay full?

 

[cq]

I had a 115 with oil injection and the oil tank had to full, so every time I returned home I added oil, plus I carried spare oil. I know a number of people who converted back to oil/gas mixture instead of injection.

 

[firedog978]

I recently bought a used bass boat with a 2003 Mercury 200hp EFi. Serial number OT773879. While installing a fish find I discovered that the alarm had been unpluged. I pluged it back in and received a low oil alarm 4 beeps about a minute after leaving the key on. I checked the tank under the hood and it was down 2 inches. I filled it back up and I no longer get the alarm. I contacted the previous owner (who had failed to tell me about this and said he didn't unplug the alarm) and he said he had on occasion put oil in that reservoir. So there is repeated oil issue. What could be the causes of the reservoir tank not stay full?

I've read your post several times to make sure I understand your issue.
The oil reservoir should use oil whenever your engine is running. It's purpose is for lubricating so you don't have to mix oil in your fuel.
It seems a bit odd that 2" low would trigger the 'low oil' warning but, I'm not sure how much your oil reservoir holds.
Mine has a very tall oil reservoir and doesn't sound an alarm until I'm down to about 1/4 remaining. I also carry a gallon of oil onboard all the time.
But, I also top off the oil reservoir before I take the boat out each time.
If you think you do have a problem might be best to check with a Mercury mechanic.

 

[David Romano]

I've noticed when the motor is tilted up for travel on the trailer some oil can escape the oil tank out the vent, it ends up in the foam insulation of the engine cover. Check your ignition switch for tightness, I had alarm issues, tightened the nut that holds the switch in the dash and issue stopped. I have a 98 Tracker 175 with a 75hp Merc/Tracker

 

[Scott Hammer TOXIC]

Your oil is vacuum fed. Yes, a 2 inch drop in your saddle tank will set off the alarm. Did you refill it per the mercury guidelines? Make sure the large oil holding tank in the bilge is full. While on the water or on the muffs, with the engine running, remove the small cap on the saddle tank oil reservoir and let it fill itself by pulling oil from the bilge reserve tank. When at the top and actually slightly overflowing, put the cap back on the saddle tank and wipe off any excess. If after that, your saddle tank drops the level, you have either a bad cap/seal on your bilge oil tank, your saddle tank or an air leak in your oil feed line or if you are unlucky like me, you have a hairline crack in your saddle tank that does not leak oil but un-pressurized the system.

 

[Scott Hammer TOXIC]

Let me backtrack and ask a question...Do you have the remote oil fill or just the saddle tank on the motor?

 

[Jim B]

Tox, you have it right. All of the big v6 motors need the external tank, the saddle tank would not provide enough oil to run for very long. I would check the cap for cracks and also the cap on the remote tank and the lines for leaks as well.


Sent from my iPad using Tapatalk

 

[Scott Hammer TOXIC]

Carlos just bought a new Ranger 520C with the Evinrude G2/250. He has no remote oil fill and no bilge tank. Only oil tank is on the top of the motor!! CRAZY!! 2 gal capacity.