Engine work and more.

Fuel Filter Assembly.

Yanmar fuel filter assembly.

Scanning through the workshop manual for the engine I found that the thermostat has a life of 2,000 hours (it is not on the service schedule in the operations manual!) so it was due and quite possibly overdue for replacement. But first up was the service and inspection, that all went fine until the thread on the bleed screw on the fuel filter gave up the ghost, it has always been problematical with a tendency to leak and now it would not seal with the normal copper washer and it was rather iffy without. I was unsure about how good the thread in the filter assembly was so rather than faff about finding the right bleed screw, with the entire assembly complete with a filter at £80 I opted for that.

Fitting was straight forward and I had previously invested in a large assorted pack of copper crush washers so there was no need to hunt down the right size.

Thermostat & hose replacement.

I had already replaced all of the hoses except the short piece to the thermostat that was probably original to the engine but I found a rub on the hose from the seacock to the water filter were it was too close to the engine sump being a little too long. With hose not costing that much I decided I might as well replace more and opted for a premium silicone at £10 per metre incl postage. Compared to rubber silicone hose is more resistant to high temperatures and some chemicals, is robust, more flexible and is smoother so that water can flow more easily.

Fuel filter top left, thermostat housing top centre between the two
pieces of red hose, the lower piece is the bypass hose. Water filter
left. Water pump bottom left.

It was a good job that I decided to change the thermostat because I found that the bypass hose and the outlet from the cylinder intake coupling was completely blocked with salt; had the thermostat ever been changed? It certainly had not been since the engine was resprayed after a "major service" in 2014. 

The thermostat from
"Parts4engines".

The engine is not going to overheat because of this, presumably with the bypass blocked the water pressure forces the thermostat open as on starting there was plenty of water coming out of the exhaust. Normally the thermostat does not start to restrict water through the bypass until the water in the outlet is 42°C vs a summer input temperature of 8 - 15°C  and it  should be fully open with the water temperature at 52°C  at which point it completely blocks the bypass to force all of the cooling water through the block and cylinder head.

So with the bypass blocked, the engine would be slow to warm up and probably for an extended period  would have been running even cooler than normal for a raw water cooled engine that already runs cool compared to the heat exchanger equipped fresh water cooled version. 

Wednesday 21st.

A new bag for the throw bag, the bean bag weight and line, minus
a couple of feet that has been exposed to the sun, reused.

A cover for the tiller to preserve the rather good varnish finish.
Only try this using hand stitching if you have a lot of spare time!

I think I have finished all of the winter work except a bit of painting and a couple of small jobs down below that I'll do in a month or so when I'll need to go to the boat to replenish the condensation traps, to do some cleaning and take some heavy gear down. Then it will be 2 or 3 days to re reave the running rigging and put the sails on and I'll be ready to head to Ireland.