BLUEMOMENT

Visited Sahona for the first ime in ages today and was pleasantly surprised by the general state of things - nothing missing, minimal guano, no flapping bits. The engine started first turn -which it doesn't usually do! so it was left to charge the batteries while I firkled about in general.
It sounded OK but when I later looked round the back, there was steam from the exhaust and less than usual water. The temp guage was up to about 80, only slightly higher than usual, but there was water vapour hanging about the left side of the engine and traces of coolant on the head at the injectors.
I stopped it and cleaned the raw water inlet which was a bit jelly-ish. The water now gushes from the exhaust but the engine stays hot. I also think I got a hydraulic lock while starting one of the times.
It looks as if it's come out of it's Covid coma but will never be the same again - a bit like us old folks if we're not careful.
Any thoughts anyone ? It's a perkins 4108 1978-ish, has already had one sinking, so it doesn't really owe anyone anything, but if it's likely to be something simple that I can fix let me know.
Failing that, I know someone on here (no names -no packdrill), has re-engined a sister ship and may be able to offer advice on a replacement.
Just as well we are not allowed to go anywhere for a while , it looks as if we've inherited a but-and-ben in Troon...

Aha!
We had a failed lock and steamship on a Gents cruise -coming away from Tayvallich. Para Handy - my resident engineer traced it to the vetus anti syphon device and naturally being a good owner, I allowed him to draw one out of stores which he did and all was fine after that. No water got into the engine thankfully but Chief ERA Para comforted me by saying that as the engine was as slack as a whores drawers, it wouldn't have done much damage anyway.
PM sent regarding replacement.

Going over all the evidence in retrospect, there is coolant (as opposed to seawater) lurking around the top of the engine and I added 2 litres to the header tank to bring it up to spec (but it was a long time ago I last looked) There is a crucial piece of evidence that will have to wait for next time: There is liquid leak from the dry part of the exhaust between the engine and the bell where the seawater is injected, so, either the bell is knacked or the liquid is coolant from the engine via a crack in the block or head - hence the steam. I'll need to check what the liquid is.. The engine's warrant has been signed anyway I think. Can I ask which gearbox you use on the beta and does it align with the shaft or are there U-J's . Also, is the engine maintainable via the panel under the saloon step? I notice that you have to remove seawater plumbing in order to change a fanbelt, I guess I would fit a spare round the pipe before installation. Looking at the figures (and your fine post on here previously) I like the idea of beta, have no respect for yanmar, but I think I might go for the 38- just looking at revs, torque etc. Interested in your views esp the gearbox.