1985 omc steam exiting from prop hub?

[krboater]

I have a 1985 omc 350CI 260hp that when run out of the water with the water muffs on I get steam exiting from the prop hub. No water just exhaust and steam. I do get water and exhaust from the usual discharge point between the outdive and the transon mounting braket but I do not think that I should have steam from the prop hub just exhaust. The compression is all over the board from 145 to 110 to 90 to one dead cylinder at 5. Head gasket?

 

[KaGee]

Re: 1985 omc steam exiting from prop hub?

1) Steam/water out of the hub is normal

2) Your compression readings should be within 10% of each other. It would be nice to know the compression on each cylinder. If your readings are correct, your problems may be worse than a gasket.

 

[krboater]

Re: 1985 omc steam exiting from prop hub?

Ok now I know that the steam is normal. The compression is #1 145, #2 90, #3 110, #4 130, #5 130, #6 100, #7 150, #8 5. What does that tell us.

 

[KaGee]

Re: 1985 omc steam exiting from prop hub?

What led up to your problems?

The readings definetly point to a problem on the port bank.
Have you pulled the valve cover to inspect?

 

[krboater]

Re: 1985 omc steam exiting from prop hub?

Well long story short. A few years ago the engine overheated and got water in the oil due to pluged exhaust manifolds. I replaced those, changed the oil several times and nursed her back to life. Now the oil stays clean, the plugs look great but the engine is hard to start when warm and quits when ideling. Also backfires when exceleratiing. Although when I do get an plane the engine sounds great and pushes the boat along just fine. I did take the valve covers off and everything there looks good.

 

[fourwinnsdook]

Re: 1985 omc steam exiting from prop hub?

Doesn't sound like ther's much of an easy fix for that, i'de take the heads off, change the gasket, maybe put some new rings in it. if not you can try some sort of engine sealer (maybe a little marvel mystery oil) in the bad cylinder.Try to loosen or seal those rings back up. Sounds like it's about time for a whole rebuild.

 

[Manipulator]

Re: 1985 omc steam exiting from prop hub?

Probably just needs a valve job. Yank the heads bring to machine shop, reinstall. Rings are probably fine, take a look at the cylinders once you yank the heads, see what shape they're in.

 

[Manipulator]

Re: 1985 omc steam exiting from prop hub?

Probably just needs a valve job. Yank the heads bring to machine shop, reinstall. Rings are probably fine, take a look at the cylinders once you yank the heads, see what shape they're in.

 

[krboater]

Re: 1985 omc steam exiting from prop hub?

ok, taking the boat to engine shop to pull the heads. I will keep you all posted as to what the results are.

Thank you again for all of your help!

 

[Coors]

Re: 1985 omc steam exiting from prop hub?

but the engine is hard to start when warm and quits when ideling.
Carb? along with other problem?