Mercruiser 7.4 L V8 Bravo

[Cashs Eliminator]

My recently purchased Mercruiser 7.4 L V8 Bravo powered Eliminator as not been started in at least 3 years, I checked the oil and it appears to be contaminated with water (milky appearance). I pulled a spark plug and it is black but shows no rust or corrosion. Would the engine internals see enough condensation from any source to contaminate the oil?

 

[Scott Danforth]

Most likely not

Change oil

Drain water jacket

Pressurize the cooling system to see if you have a leak. If it holds pressure, run it and check oil

You should have insisted on a seatrial

 

[alldodge]

My recently purchased

Sorry to hear

 

[tpenfield]

:welcome: to iBoats. . .

In hindsight, you may have wanted to join the forum before you purchased this boat. Milky oil, not started in 3 years are red flags that would have needed further investigation before committing to a purchase.

Can you share more details on the boat history and purchase process.

As Scott indicated, you should get new oil in there, do a pressure test on the cooling system to determine if you are getting water in the oil from a cracked block or manifold.

What year vintage boat/Mercruiser 7.4 is this? I've had a 1991 7.4 carbureted (Mark VI block) and now have twin 1996 7.4 MPI (Gen 6 blocks). The 7.4 / 454 engines are fairly 'bullet proof', but no match for freeze damage, just like any other engine.

 

[scoflaw]

Without knowing what he paid for it, you can't really say if it was a bad decision or not.

 

[Cashs Eliminator]

7.4/V8 Bravo in early 90 Eliminator

Bought 21 ft Eliminator bowrider with big block V8 that has not been used for over 3 years. Engine has 276 hours on meter. Found oil to be contaminated with water i.e., slightly milky. Normal after extended non-use? Oil/water separator issue? Boat came with no documentation. What is best method to change oil? Suck it out through dip stick?

 

[Fun Times]

My recently purchased Mercruiser 7.4 L V8 Bravo powered Eliminator as not been started in at least 3 years, I checked the oil and it appears to be contaminated with water (milky appearance). I pulled a spark plug and it is black but shows no rust or corrosion. Would the engine internals see enough condensation from any source to contaminate the oil?

]Bought 21 ft Eliminator bowrider with big block V8 that has not been used for over 3 years. Engine has 276 hours on meter. Found oil to be contaminated with water i.e., slightly milky. Normal after extended non-use? Oil/water separator issue? Boat came with no documentation. What is best method to change oil? Suck it out through dip stick?

Cashs Eliminator , Just wanting to let you know here's your original topic you created yesterday that may had been overlooked evident of the second topic created by you today... We put the two topics together vs deleting one of them to help keep things more Informationally organized.

Good luck with your engine problems.

 

[Cashs Eliminator]

Thanks for the responses guys. The boat was stored in my daughter's yard and basically abandoned. It has a sound hull and in generally nice shape. Her husband, who is on extended service OCONUS, bought it for 3K as a favor to the PO. I had a lot of experience working on my Son's 1980 28' Bayliner with a small block and I/O several years ago but this boat is more sophisticated. Sorry about the double posting, I had trouble logging on today so thought I'd lost the original post. The engine is carbureted, 4 barrel

 

[Luv2fish36]

If it's been sitting on a trailer neglected for three years there may be a chance the bilge filled up with rain water at some point. gets high enough it would find its way into the oil pan. Usully doesn't mix tho.

 

[Scott Danforth]

neglected boats are the most troublesome.

 

[Cashs Eliminator]

I thought the engine might be seized, couldn't get it to turn with the starter, so I made a tool to turn the crankshaft pully. I was able to turn it enough with the tool to loosen it up enough to spin it. Next step is to replace the plugs and see if it will start.