66 Merc 50 Strange Color Water on Muffs

[Alumarine]

Hi. Haven't worked on an outboard since 1974 and have a question about my 66 Merc 50 project boat.

Finally got the engine running, and noticed while on muffs that the water coming out of the drive was milky.

The color is hard to describe but it almost looked like concrete slurry if that helps. Not the thickness of it, but the color.

Any ideas?

 

[studlymandingo]

Re: 66 Merc 50 Strange Color Water on Muffs

water and oil mix​

 

[Alumarine]

Re: 66 Merc 50 Strange Color Water on Muffs

water and oil mix​

Thanks Stud.

When you say water and oil mix, do you mean oil from the fuel, or oil from the drive?

 

[Scaaty]

Re: 66 Merc 50 Strange Color Water on Muffs

I'd do a compression check. Make sure all cyclinders are close to even. Ya might have a cracked or warped plate in there, letting cooling water into a cylinder. If so, it will have rusted up a ring, lowering compression..
Let it warm and run for awhile also too..might clear up. A pic of what it looks like would help

 

[Alumarine]

Re: 66 Merc 50 Strange Color Water on Muffs

Scaaty, yes a compression check is in order.

I'll see what the numbers are.

 

[cweaver]

Re: 66 Merc 50 Strange Color Water on Muffs

hi... i have a 1977 50 mercury and mine was doing same thing.... open cover and see if any of the milky white is blowing back out of carb....if so i found out i have a bad reed valve....also look at all pulgs to see if any is on them...