3rd May 2022 – Dunstaffnage
40 Days to go before the Scoresby Sund Expedition starts
Warning: This is a very boring technical post
It was raining so I decided to work on the engine. I had changed the oil at the end of last season but I decided to leave changing all the filters and the rest of the chores until the boat was back in the water. I was a bit concerned that if I changed the fuel filters ashore there may be a little air bubble in the system and the poor donker would be starved of fuel and clap out on me during the adventurous little trip around the marina to my pontoon. That would just be embarrassing.
So whilst she was afloat I changed the oil filter, the two fuel filters, checked the impellor and the water filter, changed the gearbox oil and filled up the stern tube greaser. All went well until I tried to bleed the fuel. I eventually found the little hand lever that I needed to pump as there is no electric pump on this installation. I pumped furiously and a tiny bit of diesel and some bubbles came through the appropriate bolt but then sadly no more. I pumped away but nothing was happening.
I decided to sleep on it, not literally – that wouldn’t help, but just hoping some inspiration would come in a dream. My dream wasn’t technically inspiring, so I started to seek advice from all the helpful people in the yard and in the Alba Sailing Shop. Lots of helpful suggestions were made:
- Put in a primer bulb (I didn’t really fancy this as it would introduce two more joins in the system)
- Try blowing back through the tubes to see if you can hear bubbles in the tank (good idea but Beta use fuel clips on the hoses which are above my pay grade)
- Put in an electric pump (my old engine had a pump, it failed once but I had fortuitously stowed a spare onboard. I’d rather not have an electric pump unless really necessary. I checked the height of the engine against the fuel tank and it was within limits – just. However, the tank was full so there was no reason good old gravity shouldn’t work)
- Undo the pipe to the primary filter and check diesel is flowing through (I did this and the fuel did come out, but on reflection, considering the tank was full, it didn’t exactly gush forth)
- Keep pumping it might take 15 minutes (15 minutes is a long time to pump that little lever but I did my best – maybe ten minutes)
- Rotate the crank slightly because the cam can block the diaphragm (I did this slowly while pumping but couldn’t feel the difference. However, it might have helped but can’t be sure).
I also had in my mind the idea of pressurising the fuel tank which was something I had come across for people searching for minor fuel leaks. As a last resort I felt this might help, and one way to do it, I thought, would be to pump air into the breather tube. So, I decided to investigate what size hose would fit on the breather pipe. Admittedly, at this stage, I had no idea how to pump the air in. When I felt the end of the copper tube it felt soft and globular. I discovered it was blocked with a big lump of varnish which must have wiped off my brush whilst varnishing the area. If someone had asked “Do you think you can seal the end of this 6 mm pipe with a blob of varnish?” I would have said “No chance!” but there it was.
I cleared away the offending lump with a galvanized clout nail (unnecessary detail!) and low and behold diesel gushed forth when I began to pump. It is hard to say exactly what cured the problem, it could well have been a combination of things, but I was certainly very happy to hear the donker chugging away again!