Mercruiser raw-water heebeejeebees

[svtosca]

On the verge of buying, but raw water cooled engine -- though clean as clean can be with full service records, etc. -- scares me. Can anyone tell me how many hours (or years), realistically, you can expect from a professionally maintained and meticulously serviced, raw-water cooled Mercruiser I/O? Or better yet, any long-livin' raw water cooled Mercruisers out there? What's a conversion to closed cooling go for on a 5.7L?

Thanks.

[nestorpr]

Well, my engine is an original 1970 Mercruiser raw water cooled and it's still in fantastic condition inside. It was rebuilt in 1999 but still has all its original metal cooling parts, there was no need to replace any. Now there's no rust when I flush it after a day out and the temperature never rises above 145-150 degrees no matter how hard I ride it, 148 is normal temp. Of course, it's always flushed after every use and I'm planning to start using one of those flushing products in the future. That's 35 years baby and who knows how many more! [img]/images/graemlins/grin.gif[/img]

[Rhodnett]

My '74 SF 23 has a '93 5.7l Mercruiser raw water cooled with 730 hrs. I bought the boat from a friend last year, and I don't know how often or if it was flushed after use. During the course of having the oil pan replaced (rusted around the drain plug), the risers had to be replaced....the ends where the hoses attach were rusted and falling off. Other than that, everything looked OK...(as far as we could see, that is).

[svtosca]

thanks guys. I'm off the I/O kick and now contemplating inboard vs. outboard.