I'm starting year three with a Yanmar 3YM20 - love it, of course.
As well as changing the oil and filter, changing the tranny fluid, changing the impeller (that's another story, premature failure), checking the belts (and carrying spares) and changing the coolant, all according to the official recommendations ...
... there's the issue of fuel. I'm just buying diesel at PetroCanada, which as far as I can tell from their website meets all of the arcane specifications listed in the owner's manual.
I bought a high-tech filling-filter to use which is supposed to remove everything from the fuel except fuel (www.mrfunnel.com)
. With some difficulty I have just changed the primary and secondary fuel filters (and the primary had a little gunge in it), and several experts I know are alarmed at how many diesel boaters don't do this regularly.
I don't know what I'll do when it comes time to clean the tank (and when will that be and how will I know?), because it might require pulling the engine on my boat. The tank was cleaned 2 years ago when the new engine was installed, and very much needed it, I learned.
So, I "hear" from supposedly authoritative sources that I should be putting all sorts of things in my fuel, including lubricants, water-removers, stabilizers, goodness knows what else, and ... biocide.
However, the owner's manual says very clearly "Do not use biocide." It doesn't say why, or what to do instead.
My feeling is that most people missed that page and do use biocide.
So, that's my question: what are the right things to put in diesel fuel?
"Stanadyne Lubricity" has been suggested to me, as a start, by a marine professional.
I live in a temperate climate on the St. Lawrence River, warm Summers and cold Winters, and put about 60 hours on the engine a year (and get much more sailing that that!).
There are other questions, particularly to do with Winter storage, but I can get back to that later, if needed.
1981 US Yachts 33