Steve56

As far as I'm aware they finished doing anything some time ago.

At the time I was working as a self employed marine engineer and covering warranty work for Isuzu Marine as well as a few other major engine companies. Isuzu Marine have now become Engines Plus. Therefore all parts would have been supplied by them, and all genuine Isuzu parts. I don't really know what the parts availability is, but if stuck you could call Engines Plus and they may be able to advise.

You are quite correct. The early Isuzu 55's did have an issue with head gaskets blowing. This was only an issue on the 55's and did not affect any of the other models. At the time the fix was to repair using a modified head gasket as supplied by Isuzu. I have done a number of these in the past and once fitted with a modified gasket there were no further problems. It was also recommended by Isuzu to replace the stretch head bolts at the same time.

I've spent my whole life as a marine engineer. I certainly wouldn't claim to know it all. You can always learn something new, or a different way to go about things. If someone claims to know it all there probably best avoided.

Should definitely slope uphill or have a Swan neck. Over the years I have had a number of boats with wrecked engines due to water down the exhaust. Just poor workmanship by the builder/engine installer.

Definitely imperial as indicated with the shoulder at the top. Metric fittings have the shoulder at the bottom. On odd occasions some of the manufacturers nowadays don't seem to bother with this. The pipe in the photo is probably 5/16. Don't mix and match metric and imperial fittings, it's just a bodge and is asking for problems further down the line. I would say the problem you have is that the pipe coming from the tank has a tapered thread and your fitting has a parallel thread. Obviously been forced on and caused the split. As someone else has already mentioned you should really have a ball valve fitted in the return line.

Here is the relevant page from the parts manual. You can see the o-ring under the coupling. The only thing I did get wrong is the fact that the coupling securing nut is castellated and held in place with a split pin. It must just be the smaller boxes that have a nylon.

It sounds as if the oil is leaking along the output shaft and through the inside of the output coupling. Therefore not the output oil seal leaking. If I remember correcty when the output coupling is removed there is an o-ring on the shaft which stops the oil. Also when fitting the coupling it pays to put a little flange sealant on the flat washer that fits below the retaining nut. It may also pay to check that this coupling nut has not worked loose. I have come across this a number of times. It doesn't take much for an oil leak to start. If you take this apart it will pay to fit a replacement lock nut and ensure the correct torque setting.

What sort of noise are you getting. Could it possibly be a singing prop.

Can confirm that when I passed by at the end of last year it was still closed. But apparently sometime in the near future the pub at Haw Bridge will reopen.

It looks like a steel bar welded to the hull for clipping cables, pipes etc. A few boatbuilders do it this way.

May be worth checking all the electrical connections and the plugs and sockets on the loom. It could just be mild corrosion due to dampness and the time the boat has been standing.

I may be stating something you are already aware of. The coupling in the photo is definitely metric. On the R&D coupling the line you can see machined around it indicates it is metric. An imperial coupling woud not have this.

I have a friend who painted the decks of a fiberglass sea going fishing boat with chlorinated rubber paint. He absolutely swears by it. Says it is very hard wearing and keeps its colour well.

If its anything like the workers that turn up on my local canal I bet they all have a personal CRT vehicle to get to site.