salt water drives/engines... outward signs of quality?

[banfield]

Hi Guys,
I'm going to look at a boat that has a used drive and motor with mostly unknown history recently installed in it. The one thing that is known is that the drive and engine were (separately) used in salt water in the past. They are both roughly 1989 vintage, a 454 and a bravo I. Both look pretty good on the outside from pictures, and both function correctly. The engine runs cool with good compression and no excess water vapor in the exhaust. The manifolds 'looked good' as is, the risers are new as is the water pump. The water channels in the drive were clean.

My question is: what specifically would you look at to try to ensure the quality of the drive and engine with respect to salt water damage. Consider that I am a buyer and can't do much invasive to check things.

Thanks for the wisdom... I'm totally inexperienced with salt water. Am I stressing on this too much?

[Morgan's Cloud]

HI ..
I guess my question would be.. Did this 'package' live in the salt water or was it just used in salt and trailered/flushed etc ?

If it was trailered all of it's life and flushed then there should be no antifouling paint on the lower unit facilitating inspection.All surfaces should still have good factory paint on them with little scratching and corrosion/electroysis.
If it has been antifouled however real condition will be harder to determine as a great many people don't invest the time to do it properly and are known to regularly slap more paint over areas that need refinishing.
Make sure also that all of the ground straps are visible on the unit ..I think there are 3,maybe 4.
Where I am ALL boats live in the water and it is so salty it's more like acid.I don't particularly like it but with LOTS of maintenance we keep up with it.Just can't beat those old Volvo 250/270/280 drives though for salt durability.

One other word ... if you buy this boat DON'T trust the factory cast iron exhaust manifolds no matter how good they look.Merc manifolds are notorious for leaking internally at the manifold/riser joint and self destructing your engine. I just saved my 502MPI by about a week and I've been aware of this problem for many years.
There are plenty of other salt water Donzi here (although I don't think any of them have to leave their boats over like we do).. I'm sure there will be plenty said from the others.
Good luck !

[MOP]

Being an 89 I think you have the early OMC King Cobra unless its been change out. It is a pretty good package not quite a good as the later models. Any how if the zincs were kept up and it had fairly decent care it should be fine. Two things one already mentioned buy riser gaskets drain the manifolds and take it apart at the riser, if the guy will let you, that is the only way to tell how good the meat is plus you will have checked a common problem. Pull the lower oil plug in the drive, it should have a magnet which grabs the floating junk. A very little dark muck is Ok, but any bright particles its on its way out. Last but not least buy an Oil sample kit at West marine take an oil sample from the engine and send it of, it only takes about 4-5 days for results. If all that stuff looks good heck I would go for it.

[banfield]

Thanks for the input!
The hull is actually an '83, but the engine and drive are from some other pair of boats, and from about '89. They really are Mercruiser's 454 and Bravo I, even though Donzi wasn't using Mercruiser itself at that time.

[MOP]

That Bravo package is a good one, just be careful to keep up with the zincs and make damn sure they get a good bond. Not sure why but the Bravos around here and from what I have read seem to eat up the skegs. I read a post awhile back that Merc was finally owning up to it. My Bud up at the 1000 islands has a 2001 26ZX that is trailered most of the time and has never seen salt, it has a rat bite out of its skeg already.