burnt lower unit oil

[Stevo]

I have twin 1997 Merc 150 EFI's.

Problem #1
Starboard engine lower unit oil is milky-brown.
I can pump in about 28 ozs. of replacement gear lube oil.

Problem #2
Port lower unit oil is black & has burnt smell.
Also, can only pump in 4-5 ozs. before it flows out top screw.

All 4 washers are new and have been replaced past two years.

Can anyone help with these two problems?
Any ideas what is going on & what I might need to do to correct?

I will take both lower units apart to repair if necessary.

Stevo

 

[Laddies]

Re: burnt lower unit oil

Your starboard unit has a leak, since you did not meantion oil a the prop shaft it must be the drive shaft or shift shaft seals. You will need to drop the unit a lok better yet have it pressure tested so you know where the leak is for sure. Black oil that smells burnt is quite common drain it and refill with synthetic gear lube.