[C320-list] Lessons learned (not quite the hard way) about fuel management.

[Graeme Clark]

Hopefully this little tale might help someone in the future…

So, it finally happened, I ran out of fuel!

All my own fault. Ever since I bought ‘Jaskar’ the fuel gauge has been pegged against full. The previous owner told me that the wrong transducer had been fitted and that the gauge would start to indicate once the tank was about half empty. So putting in a new gauge went on my list of things to do, but as we all know, the tank isn't the easiest thing to reach so the job kept getting put off.

However I kept careful records of fuel added and logged the tacho hours total when I topped up so I had a good idea of my consumption, both when  motoring around the marina and on extended trips with higher RPM.

I made it a point to always fill the tank at the dockside pumps before going home after a spell onboard so we always started with a full tank next time.

What could possibly go wrong?

Well, what went wrong was that the tacho hours meter broke. I realised that although the needle correctly indicated engine RPM I was no longer logging engine hours. I ordered a new tacho but in the meantime we carried on enjoying our summer on the water.

Cutting a long story short, somewhere in all this, I didn't fill up when I thought I had filled up and then off we went on a 12 hour motor sail to the "Isles of Scilly”. For my US cousins who don't know it,  this is  a small set of islands just off the southwest tip of England where there are a lot of hidden and shallow  rocks and a big tidal range (15 ft difference between high tide and low tide). At low tide you can sometimes walk across the sand  between islands and at high tide sail between them  over the same place. So - in short - not a place to be without an engine!

So  -  on a near windless day we decided to motor down to "Bishops Rock" - the most westerly part of England, basically a lighthouse on a rock in the Atlantic Ocean! 
(google maps here if you want to look: https://goo.gl/maps/zTUMpirb2652 <https://goo.gl/maps/zTUMpirb2652>)

And by my reckoning we still had half a tank left. Except of course we didn’t.

So inevitably the engine stopped. There was about 1 knot of wind so we couldn't sail. There is a significant current of around 1.5 knots sweeping us slowly towards shallow rocks about a mile away!
The gods smiled on me. A navigation buoy was within reach and we got a line to it and moored up.

I went below to see what the issue was. At first I assumed it to be  blocked fuel filter. (although we put in a gallon can of fuel that we had on board, to be on the safe side) So I changed that. I have never changed a fuel filter on my engine before although I had done so on a similar (Racor) installation fitted to my previous 320, which had a Westerbeke engine.

The problem now is that whilst the Westerbeke was self bleeding. My Yanmar 3GM30F is not. So that was another first for me.

The final problem was that as the tanks level had dropped, the fuel pipe and sucked in some floating debris into the filter housing inlet and that had blocked it.

I ended up dismantling the Racor filter head unit and blowing everything out with our inflatable dinghy foot pump.  We also used the foot pump to pressurise the fuel tank (remember to block the vent fitting on the transom) to get the fuel flowing again to the filter head.

I had no real idea how to prime the fuel system and bleed it. I had to read the Yanmar manual there and then onboard, with my head in the aft cabin trying to work out what did what. But although I had the Yanmar manual, I  had no instructions about the Racor unit, so had no idea what to do with it!

Again, the gods were smiling because the lack of wind meant that all this was being done in a flat calm. For that reason and that reason alone we managed to sort it all out. If this had happened in a heavy sea, i would have had no chance.

So the point of this post is to URGE, HARASS, and NAG you all to do the following, (if you haven't already) and  to do this in the dock when there is nothing else to worry about:- <about:->

* Learn how to change a filter on the fuel system, both the pre-engine and the actual engine filter
* Learn how the fuel filter head fitting works. The racor has a bleed screw and a priming pump -  do you know how to use them? Consider taking it apart to really understand it.
*Learn where the bleed points are on the rest of the system - make sure you carry the correct sized wrenches and screwdrivers to open them.
*Have a  blunt ended flexible rod or wire that you can poke back along the rubber pipe towards the tank to remove any blockage
*Actually carry out the whole process  - or get a mechanic to show you how.

I reckon that having done it once - in calm conditions - I could now change a filter and bleed the system in a reasonable sea. I could do it by feel rather than by needing to look at a manual and then seek out the relevant part on the engine itself.  It really is worth the effort to learn the system. I was so lucky in when and where it happened.

Oh - yes I almost forgot -  fit a working fuel gauge and never trust what the previous owner has told you!

Graeme
‘Jaskar’, 1996 #366. Falmouth UK.