Using a biocide along with Star Tron

[EmeraldCoastSailor]

I have used Star Tron Enzyme treatment for years but I recently discovered a few bugs in my primary filter (after 20 hours of polishing). My tank configuration, plastic with no access panels, leads me to think only removing tank from would allow a deep cleaning. My plan is to shock treat with Biobor JF Biocide and continue polishing until primary filters are clear. My question is whether or not it might be harmful to engine to run on fuel with both biocide and Star Tron in it. 11.5 year old boat with 20 gallon tank located in FL. If not a problem then perhaps use both in maintenance mode going forward?

[sailorboy1]

If you add the labeled dosage amount it wouldnt be a problem

[capn_billl]

I just read through my owners manual for Yanmar Diesel 4JH45 it stated specifically, "Do not use biocide in fuel".

Why?

I use Diesel biocide in my Kubota regularly without problems, the fuel stays clean, and yellow.

I know the Yanmar is electronic, does it interfere with a sensor?

[capn_billl]

Originally Posted by EmeraldCoastSailor

I have used Star Tron Enzyme treatment for years but I recently discovered a few bugs in my primary filter (after 20 hours of polishing). My tank configuration, plastic with no access panels, leads me to think only removing tank from would allow a deep cleaning. My plan is to shock treat with Biobor JF Biocide and continue polishing until primary filters are clear. My question is whether or not it might be harmful to engine to run on fuel with both biocide and Star Tron in it. 11.5 year old boat with 20 gallon tank located in FL. If not a problem then perhaps use both in maintenance mode going forward?

I would look up the active ingredients on both, and call the manufacturer, and ask, or Google for interactions.

[EngNate]

The other time I've heard this 'no biocide' was with MAN engines and the explanation was: Some of the killed organisms leave tiny skeletons that pass through filters and are abrasive to the injection system components.

[CarlF]

It's fine. In fact Mack Boring, the master Yanmar distributor for the US East Coast, recommends and sells biocides for Yanmar's. Mack arguably knows more about Yanmar engines in boats than the guys writing the manuals in Japan. Mack is also who pays warranty claims.

I add both a maintenance dose of Biobar biocide and a fuel treatment at every fill up except when I'm taking on Valvtec fuel - because Valvtec already has biocide and other additives mixed in. If Yanmar owners couldn't buy Valvtec fuel they'd have a real problem getting fuel in some parts of the US.

One reason a fuel treatment is a good idea is that today's US diesel is quite different from the diesel of 15 years ago because of EPA regulations. European diesel has considerably higher cetane.

Since you only have a small problem, I'd first try just a regular dose of biocide and see if that does the trick. And have plenty of spare filters available. After your first trip in rough water a lot of dead algae may get nocked loose and end up in the filter.

Here's the Valvtec description:

ValvTect - Marine Fuels

[skipperpete]

Originally Posted by capn_billl

I just read through my owners manual for Yanmar Diesel 4JH45 it stated specifically, "Do not use biocide in fuel".

Why?

I use Diesel biocide in my Kubota regularly without problems, the fuel stays clean, and yellow.

I know the Yanmar is electronic, does it interfere with a sensor?

Hi capn_bill
I also have heard that biocides were not recommended for common rail engines but didn't really know why beyond the fact that the critical particle size for an electronic injector is <>2 micron so I did a bit of reading.... one reason for Yanmar's position re biocides might be that all biocides are not the same, some contain alcohol and glycol which bonds with water in the bottom of the tank and suspends it in the fuel allowing it to enter the high pressure system causing damage to the injectors that would not occur with "dry" fuel. A conventional fuel injection system would be less affected by the moisture but the Bosch common rail system on the recent Yanmar's and Volvo's is very fussy about dirty fuel.
The OP is doing the right thing with the dialysis loop but with only 20 gallons of total fuel, a tank washout and fresh fuel is also a reasonable option

[skipperpete]

Oops half of my post vanished..... the guts of it was that emulsification of water in the bottom of the fuel tank by SOME types of biocides causes damage to common rail injectors, Yanmar is simply following the fuel system manufacturer advice( Bosch) by suggesting that biocides is a bad idea in this instance. The attachment is from a company that makes test kits for biocides levels in diesel fuel.... too much is not good.

[steamgoat]

For the past 5+ years I have used Startron enzyme and biobor JF together on a recommendation from practical sailor. I run a 2 micron filter with a vacuum gauge and,fingers crossed,have had no problems so far, even with various Bahamas fuel supplies.

[a64pilot]

I too mix them and run Bio-Bor jf with every fill. And if it sits for a few months I dose to the shock level. The tanks on my bow are also treated to the shock level and they get emptied out into the large tank at the end of a cruise and refilled at the beginning of the next.
I bought my boat with a “bug” problem, they were dead bugs but still it was a pain.
I seriously doubt that a home brew polishing system will do much of anything as bugs typically are of a consistency of snot and stick to the tank walls, they aren’t floating around in the fuel in tiny little balls waiting for a polisher to suck them up, they are often a film on the tank wall, that builds up and some will fall off and that’s what gets into filters.

Once you kill them and they fall off, then they can be filtered. The dead bugs in my tank when I bought the boat looked like Tofu, or cottage cheese or something and were the color of cardboard, but they were dead.

[S/V Illusion]

Originally Posted by skipperpete

Oops half of my post vanished..... the guts of it was that emulsification of water in the bottom of the fuel tank by SOME types of biocides causes damage to common rail injectors, Yanmar is simply following the fuel system manufacturer advice( Bosch) by suggesting that biocides is a bad idea in this instance. The attachment is from a company that makes test kits for biocides levels in diesel fuel.... too much is not good.

The above is quite correct. Using fuel additives in most cases is a “feel-good” approach which doesn’t do much good and can sometimes cause problems which wouldn’t normally exist.

Diesel fuels are refined with sufficient additives at the refinery to ensure quality of the fuel which typically remains stored in those huge tanks for a prolonged period at the terminal awaiting transport to fuel stations for purchase. Adding more serves no real purpose but marketing and advertising to the general population unfamiliar with the realities is an effective means of creating false perceptions = increased profit.

If you want to manage your fuel properly, ensure the tank is clean, the tank is devoid of any water and add a cetane booster. The rest is useless.

[johnss]

May I ask a question please as new to this site.
last year, 2019, I was unable to use my boat, a Jeanneau 50DS, due to illness and so left her on the hard in a yard in Greece, where she has been since 29th Oct 2018. Going back in the water 1st May 2020 so 18 months out of the water.
Winterised pretty well including emptying water tanks, filling fuel tank to the brim, service engine etc etc.
My question is will the 240 litres of diesel to which I added slightly over the recommended amount of biocide (brand unknown) be OK when we return in April? The temperatures in Greece in the summer sitting in the sun all day will get pretty hot.
I would not want to dispose of the fuel as that would be very expensive to have removed.
one other question, what would you recommend to flush out the water tanks 650 litres in total, as they are bound to be very stale.

many thanks for your help.

[S/V Illusion]

Originally Posted by johnss

May I ask a question please as new to this site.
last year, 2019, I was unable to use my boat, a Jeanneau 50DS, due to illness and so left her on the hard in a yard in Greece, where she has been since 29th Oct 2018. Going back in the water 1st May 2020 so 18 months out of the water.
Winterised pretty well including emptying water tanks, filling fuel tank to the brim, service engine etc etc.
My question is will the 240 litres of diesel to which I added slightly over the recommended amount of biocide (brand unknown) be OK when we return in April? The temperatures in Greece in the summer sitting in the sun all day will get pretty hot.
I would not want to dispose of the fuel as that would be very expensive to have removed.
one other question, what would you recommend to flush out the water tanks 650 litres in total, as they are bound to be very stale.

many thanks for your help.

Depends on if or how much water got into the tank promoting growth. Depending where you are in Greece, there are folks who can filter and return the fuel to your tank which would be prudent as well as adding a cetane booster depending on what engine you have.

[johnss]

Originally Posted by S/V Illusion

Depends on if or how much water got into the tank promoting growth. Depending where you are in Greece, there are folks who can filter and return the fuel to your tank which would be prudent as well as adding a cetane booster depending on what engine you have.

The boat is on Leros, Dodeconese Islands. The tank was filled to the brim to avoid condensation. the engine is a Yanmar 4JH4HTE 110hp turbo. I will find out from the yard if the fuel can be filtered.
many thanks.

[MJH]

Originally Posted by EmeraldCoastSailor

I have used Star Tron Enzyme treatment for years but I recently discovered a few bugs in my primary filter (after 20 hours of polishing). My tank configuration, plastic with no access panels, leads me to think only removing tank from would allow a deep cleaning. My plan is to shock treat with Biobor JF Biocide and continue polishing until primary filters are clear. My question is whether or not it might be harmful to engine to run on fuel with both biocide and Star Tron in it. 11.5 year old boat with 20 gallon tank located in FL. If not a problem then perhaps use both in maintenance mode going forward?

While Bibor JF is Practical Sailor's recommended diesel additive few know of the SHELF LIFE. I called Hammons Fuel Additive and was told the shelf life is three years from manufacturing date whether sealed or not. That date is on the bottom of the container. So it doesn't pay to buy it in any larger volume than you will use over that period of time. I had to throw some out.

~ ~ _/) ~ ~ MJH