Marine Diesel Unused for a While

[GreggL]

First cruiser with a marine diesel so I'm still new to all of this. It's a brand new boat and I had her tanks topped off at time of delivery. It's been a few months since then and I've used only half a tank. It was used regularly up until about a month ago when I went away for a trip so it's been sitting for quite some time. Been hearing about issues with diesel left sitting in tanks, etc... What can I do in this situation? Do I even have a situation?
Thanks!

[DeepFrz]

No issue from sitting one month. However, how old was the fuel that was in the tank before you topped it off?

[GreggL]

Originally Posted by DeepFrz

No issue from sitting one month. However, how old was the fuel that was in the tank before you topped it off?

Can't be much older, the dealer put a few gallons in to run tests I was told. It was basically empty when I filled up again. Just trying to be proactive as I have a trip coming up and would love for it to be smooth.
Any advice on keeping everything nice and proper with the fuel?
Thanks!

[capngeo]

Biobor with every fueling and forget the problem

[CarlF]

That fuel will be fine.

Since you also have a nice clean tank, it will be worth a bit of effort to keep it that way. Add a dose of biocide (Biobar JF and Valvtec are two popular brands) when you fuel up. This will keep black gunk from growing in your tanks that will foul your filters and stop your engine - always at the worst possible moment. If your marina has "Valvtec" fuel, the biocide is already in it.

You might also consider a diesel additive. US diesel fuel was reformulated three years ago for environmental reasons and it ain't what it used to be. Yanmar now recommends extra lubricants and cetane. They recommend products from FPPF but there are lots of brands. Most people don't bother but it's cheap.

Carl

[GreggL]

Thank you!

[GreggL]

Originally Posted by CarlF

That fuel will be fine.

Since you also have a nice clean tank, it will be worth a bit of effort to keep it that way. Add a dose of biocide (Biobar JF and Valvtec are two popular brands) when you fuel up. This will keep black gunk from growing in your tanks that will foul your filters and stop your engine - always at the worst possible moment. If your marina has "Valvtec" fuel, the biocide is already in it.

You might also consider a diesel additive. US diesel fuel was reformulated three years ago for environmental reasons and it ain't what it used to be. Yanmar now recommends extra lubricants and cetane. They recommend products from FPPF but there are lots of brands. Most people don't bother but it's cheap.

Carl

Can I use the biocide with a diesel additive? Are these things typically sold at fuel pumps or is it something I'll have to administer?

[SkiprJohn]

Read all you can about a product before adding it to your tank. Biocide is to keep things from growing in your tank that will clog your fuel filters. That's the only additive I'd put in there without reading everything about whatever you are thinking of adding.
If you have a new engine then you don't want to ruin a warranty by adding something not approved.
kind regards,

[S/V Illusion]

Originally Posted by CarlF

Yanmar now recommends extra lubricants and cetane. They recommend products from FPPF but there are lots of brands. Most people don't bother but it's cheap.

Carl

Can you show us where such a recommendation from Yanmar is published?

[forsailbyowner]

Had a diesel mechanic and a long haul truck driver tell me to clean injectors c and boost cetane they add a quart of automatic trans fluid for every 5 gallons of diesel

[S/V Illusion]

Originally Posted by forsailbyowner

Had a diesel mechanic and a long haul truck driver tell me to clean injectors c and boost cetane they add a quart of automatic trans fluid for every 5 gallons of diesel

lots of folks do that as well (add a cetane booster).

What I was wondering if there really is a Yanmar recommendation which states that additional lubricants are required?

I've heard people say that but never found any basis for it.