Mercury Lower Unit oil drain ...

[tunatamer]

I recently became the recipient of a preowned boat with a pair of twenty year old 115 Mercs on it. Recession woes have repowering this boat on the back burner so I'm looking at using these engines until my stars are aligned.

These Mercs run great here at the house but I want to get out and run them with a load on them.

I would like to change the lower unit oil first but have hit a snag. There is a plug hole ahead of the water intake labeled "vent" which I removed thinking it was the lower plug for the oil. I cannot find an "upper" plug anywhere. It has to be behind or under something I am not seeing.

Can someone help?

Thanks in advance.

 

[Laddies]

Re: Mercury Lower Unit oil drain ...

Thats the upper plug you remove and is labeled vent because the units are filled from bottom to top, to prevent air lock. the drain is the same type of screw on the bottom front of the bullet same side of the unit.

 

[tunatamer]

Re: Mercury Lower Unit oil drain ...

Thanks Laddies ....

On my small boat with a 50 HP the lower plug is directly beneath the upper hole and in plain sight but thanks to your tip I looked further under and ahead of the bullet and there I found it. LOL there were so many scratches on the bottom I couldn't see it.

Is this a great place or what?

Thanks!