05 mercury 50 efi fourstroke losing oil

larryi88

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Feb 10, 2020
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I made a run the other day after changing the oil filter and oil and ran a total of 45 mins mostly under 4500 rpms, pulled back to the ramp let it sit for 10 mins pulled the dipstick and it was barely on the dipstick. Its not showing any signs of burning oil no smoking or residue out the exhaust and i can't find a leak anywhere any ideas?
 

dingbat

Supreme Mariner
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Nov 20, 2001
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15,417
Are you sure you have an Optimax?

Thought they where 2 strokes
 

larryi88

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Feb 10, 2020
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yea its just a fourstroke efi i keep thinking of my old optimax i use to have im not sure how to edit the title of the post it wont let me
 

Alumarine

Captain
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Feb 22, 2005
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3,684
Is this a new to you motor?
If so, are you sure 10 minutes is enough time to wait?
I know the newer motors require you to use the following procedure for accurate measurement. Not sure about yours.

"IMPORTANT: Do not overfill. Tilt outboard out/up past vertical for
approximately one minute to allow trapped oil to drain back to
the oil sump. Tilt outboard to vertical (not tilted) position when
checking engine oil. For accurate readings, check oil only when
engine is cold or after engine has not run for at least an hour."
 

GA_Boater

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May 24, 2011
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What is the oil capacity including filter? How much oil did you add for the change?
 

larryi88

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Feb 10, 2020
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oil capacity is 3.17 quarts i put in 3 quarts because the manual said its better to underfill it a little if you store it tilted for long periods.It has been sitting at the house for 2 days now and its still barely on the dipstick It is a new to me engine its been sitting 2 years prior to me owning it but i changed all the fluids and impeller before running it any. Minus the oil issue it runs like a top has no power issues or anything
 

Alumarine

Captain
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Feb 22, 2005
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When you first changed the oil what was the level on the dipstick after you had run it for a minute to check for leaks?
You may not be losing oil at all, but as GA suggests might have been low initially.
In which case, add 3 or 4 ounces and see if the level goes down after use.
 

GA_Boater

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He said the capacity is 3.17 qts and put 3 qts in. He's almost 6 oz. low.
 

larryi88

Cadet
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Feb 10, 2020
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8
I get the dipstick is going to show low on oil due to only putting in 3 quarts its 3/4ths the way up on the dip stick after the change. But after i run the boat on the water for 35-40 mins and pull off the water go home tilt the engine down leave it for an hour and check it there is barely any oil showing on the dipstick maybe a quarter of an inch showing on the bottom of it. no leaks on my concrete.
 

larryi88

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Joined
Feb 10, 2020
Messages
8
I have ran it 3 times since Ive changed it and i usually put in a quart everytime I get off the water and check it at the house if that helps but i don't lose oil sitting its only after i run it does it go low
 
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