Air cooled engines can be a bit of a problem in the enclosed space of a boat and they’re noisy but water cooling can cause so much heartache that just maybe they’re better.

About five years ago I found that my engine had a tendency to overheat when it was working hard. This was something new. Looking at the exhaust outlet there seemed to be plenty of water coming out at tickover but it didn’t seem to increase much at higher revs.

 I took the strainer out and cleaned it. I took the whole skin fiting/seacock off and cleaned it. I took all the pipework off and renewed it.I stripped the exhaust muffler/water lock assembly down and cleaned it. Finally I took the top cover off the manifold cooler and cleaned out in there. Oh, there was plenty of muck in all of it but none of this made any difference at all. Not a jot. Waste of time. There is a short rubber hose between the heat exchanger and the manifold cooler , like car radiator hose. Sometimes this stuff can delaminate inside and cause a blockage. But no, it wasn’t that. I’m struggling a bit now.

Then – then I saw a half moon shaped piece of metal was missing from the hose connector on the manifold. Just broken off. Corrosion I suppose.

The piece was lodged in the elbow of the hose connector on the manifold. It just lay harmlessly on it’s side. I tried to hook it out with a screwdriver, and as I touched it it tipped up on it’s edge and partially blocked the pipe. Then fell back again. That was it. At higher revs the water had enough ‘push’ to tip it up and reduce the flow.

Sometimes the world can get quite vindictive.

Back to the present and a week or two ago I saw that the water flow was reduced again. Well I knew there’d be weed growth in the intake, so I beached her and it was pretty bad. However, cleaned out and back on the water things were no different. But this time I know where to look. Sure enough, there’s more metal gone from the hose connector. And I can’t get anything through. It’s blocked solid now. The union is fitted to the cooler with 2 bolts but they don’t want to move. Even with the cover off the manifold cooler I can’t get a ‘prodder’ into the connector. This has now become serious – that is I might have to spend money. Yes, that serious. The union’s broken and now that I’ve taken the hose off it wont go back even if I could clear the blockage. So the union will HAVE to come off. Getting some heat on it will be the next thing to try – those bolts will have to come out or I’ll have to replace the whole manifold. That’s the ‘money’ bit.

However it’s Christmas and there’s other things to see to. A bottle of whisky with a hole in it is one of them. Most of the whisky will have come out through that hole before I do anything else.

 Anyway all the shops which sell manifolds are shut for a week.