Hi Dawntreader, this is a subject I wrote about in a reply a couple of years ago under the subject of Volvo D130 saildrive, but it would come up if you search for "Mussel." Yes, the raw water strainer that was fitted as standard some years ago was a particularly poor piece of equipment, and there are plenty around that are vastly superior. Indeed I had just sold one that I had spare shortly before finding my engine was beginning to overheat. As I think I mentioned at the time, a combination of mussel shells and impeller vanes shed while under the previous ownership, had blocked some seventy to eighty percent of the tubes within the heat exchanger tube nest. So I was fortunate that no significant damage had been done. Further investigation also revealed that mussels had set up home within the saildrive cooling water intake, where they had grown to the point that they could not have got out even if they wanted to, so part of my routine maintenance now is to make sure each time the boat is lifted out that any livestock within the saildrive water inlet is fully removed.
