Mercury pro xs

[Jhenson86]

225 having a issue with my oil tank under the cowl. I am getting the 4 beep alarm every two minutes and the oil tank under the cowl is not full. I have noticed some oil in the pan. I believe that it’s coming out of the check valve where the oil line comes in from the boat tank. Would this valve leaking cause air to get in the line and not have enough pressure to send it into the tank on the motor. 

[fishinwrench]

If the engine mounted reservoir is not completely empty then the likelyhood of air in the injection pump is little to none....unless the leak is between the reservoir and the pump.   

Locate the leak, fix it,  then remove the little cap on the reservoir, start the engine and let it idle until the reservoir fills up completely.  Then screw the cap back on.....and clean up the mess.      If the warning horn doesn't shut up after that then the reservoir has to be replaced (it has a built-in sensor).  

[Jhenson86]

Thanks Wrench!  How low does the engine mounted tank have to get before it would sound alarm. Mine is only about 2 inches low from the top. Should the system stay full all the time? 

[fishinwrench]

It should stay full all the time.   It will set a "low oil" code if it gets a couple inches low in the reservoir.  Theoretically giving you enough time to "get home".

The float sender in the reservoir is a POS, they fail all the time.  A drop of adhesive holds a metal washer on the bottom of the float and the brilliant designers at Mercury think it's cute to keep using the adhesive instead of putting a clip or something on the float so the stupid washer doesn't always fall off.   And of course it's molded into the tank so there's no FIXING IT CHEAP.   You have to replace the whole reservoir.

[Jhenson86]

Well thanks for your help. What I have determined was the tank in the boat was half full so I put some oil in it started the engine and the tank on the motor filled back up. Still weird to me that half a tank in the boat reservoir  wasn’t enough to fill the one on the motor. I usually keep it topped off but let it go a bit longer this time. The only other thing I did was clean the screen in the boat tank didn’t see any blockage but there did seem to be some thicker oil on it. Started it on the hose and no alarm. 

[Ketchup]

My Merc. did the same. If it was not atleast 3/4 full, as soon as i got on plane and trimmed up, that stupid alarm would go off. Shut it off, trim down, and good to go. I learned to keep it full. 

[fishinwrench]

1 hour ago, Jhenson86 said:

The only other thing I did was clean the screen in the boat tank didn’t see any blockage but there did seem to be some thicker oil on it.

Someone has mixed the oil, switched brands, or topped off with something other than what was in there.   I see it all the time, and it requires dumping the oil, cleaning the tank out, and refilling.   The resultant "sludge" can clog up the pickup tube screen.

Always use the same oil.  You don't want a witches brew of random lubricant in the system.  

[Jhenson86]

That’s good to know! I would say that this is  likely the scenario as I bought this boat at the beginning of August and no telling what was ran it before I started putting oil in. Thanks for your info on this I greatly appreciate it! 

[fishinwrench]

YW 👍