Prior to purchase, the fuel tank was treated with algacide and drained, and all fuel filters were changed. How many engine hours should I put on it before changing the filters again?
fouled fuel tank
- Thread starter butchrobbins
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Algae builup is more of a function of fuel laying idle in the tank than engine hours. If you use your engine a lot than algae has less of a chance of forming than periodic engine operation. As a rule I change mine every 25 hrs of engine operation or every 3 months, whichever occurs first.
The best way .....
putting in a biocide into a tank will kill most of the bioburden but will leave the dead cells that are adhering to the tank walls. If you want trouble free operation and if the tank has any access or inspection ports.... get inside with a long handled scrub brush and knock all the adhering crap to the bottom, then sop out the goo with paper towels, etc. If you kill and dont physically remove the potential exists that some during a 'heavy sea state' episode that the crud will break loose from the walls and then instantly choke the filters with a 'particle storm'. Dont let some well meaning person tell you or sell you on 'fuel polishing' as if the walls are fouled with adhering debris ... the only way to get a clean tank is to 'scrub' etc. the internals. When should you change the filters? when the vac/pressure gage on the filter housing reaches a 'high differential pressure' (high gage reading) when the engine is running near 'wide open throttle'. If the filters are RAcor go to the parker.com website .... follow the links --->marine---> racor, etc. and look for the operating curve for YOUR filter model and removal retention. Use 1-2 gallon per hour fuel flow on the 'curve' ... and that will correspond to the 'change out' pressure on the gage. ... this explanation isnt all that accurate but is close enough for 'government work'. A Cleaned out tank is the solution, changing out filters often is a symptom.
putting in a biocide into a tank will kill most of the bioburden but will leave the dead cells that are adhering to the tank walls. If you want trouble free operation and if the tank has any access or inspection ports.... get inside with a long handled scrub brush and knock all the adhering crap to the bottom, then sop out the goo with paper towels, etc. If you kill and dont physically remove the potential exists that some during a 'heavy sea state' episode that the crud will break loose from the walls and then instantly choke the filters with a 'particle storm'. Dont let some well meaning person tell you or sell you on 'fuel polishing' as if the walls are fouled with adhering debris ... the only way to get a clean tank is to 'scrub' etc. the internals. When should you change the filters? when the vac/pressure gage on the filter housing reaches a 'high differential pressure' (high gage reading) when the engine is running near 'wide open throttle'. If the filters are RAcor go to the parker.com website .... follow the links --->marine---> racor, etc. and look for the operating curve for YOUR filter model and removal retention. Use 1-2 gallon per hour fuel flow on the 'curve' ... and that will correspond to the 'change out' pressure on the gage. ... this explanation isnt all that accurate but is close enough for 'government work'. A Cleaned out tank is the solution, changing out filters often is a symptom.
Depends on Engine Type, Maybe.
The Yanmar manual for my engine (3HM35F) says that the secondary filter should be changed every 100 hours whereas Racor suggestd 500 hours for the primary filter. When I last changed the primary,last summer, it was dirtier than I expected after 500 hours. I'll reduce it next time. I change my secondary as I see fit,anually, but not more than 100 hours. One of the first things that I was taught in my diesel class was...TREAT ALL FUEL AS SUSPECT FOR CONTAMINATION. This credo has, probably, reaped it's benefits over and over again.
The Yanmar manual for my engine (3HM35F) says that the secondary filter should be changed every 100 hours whereas Racor suggestd 500 hours for the primary filter. When I last changed the primary,last summer, it was dirtier than I expected after 500 hours. I'll reduce it next time. I change my secondary as I see fit,anually, but not more than 100 hours. One of the first things that I was taught in my diesel class was...TREAT ALL FUEL AS SUSPECT FOR CONTAMINATION. This credo has, probably, reaped it's benefits over and over again.
2 micron primary filter
I have a 2 micron primary filter and when I see gunk in the bowl I change filters. It seems that I start to suck some air when the filter is getting clogged. My secondary filter seems to stay clean!!!! I change it irregularly as it seems clean. Also it is a pain to have to chase out air from the system. With the primary I just refill the filter bowl with clean diesel and don't have to purge air from the system.
I have a 2 micron primary filter and when I see gunk in the bowl I change filters. It seems that I start to suck some air when the filter is getting clogged. My secondary filter seems to stay clean!!!! I change it irregularly as it seems clean. Also it is a pain to have to chase out air from the system. With the primary I just refill the filter bowl with clean diesel and don't have to purge air from the system.
I don't understand
Moonsailer, I don't understand the purpose in a 2 micron primary. Seems to me this is just asking for more problems, more maint. and more filter changes. I have my boat set up with a 30 micron primary, a ten behind that as the secondary, and the 2 micron Yanmar filter on the engine as the final filter in the system. The primary and secondary are Wix filters, with the primary as a water seperator,and are pretty large. They each hold a quart or more. Once a season I change out both primary and secondary. Have never had a problem with filters clogging up. The 2 micron Yanmar is hardly ever touched. Seems to me the progressive filtering setup is much less of a problem.
Moonsailer, I don't understand the purpose in a 2 micron primary. Seems to me this is just asking for more problems, more maint. and more filter changes. I have my boat set up with a 30 micron primary, a ten behind that as the secondary, and the 2 micron Yanmar filter on the engine as the final filter in the system. The primary and secondary are Wix filters, with the primary as a water seperator,and are pretty large. They each hold a quart or more. Once a season I change out both primary and secondary. Have never had a problem with filters clogging up. The 2 micron Yanmar is hardly ever touched. Seems to me the progressive filtering setup is much less of a problem.
filter combinations
I think Nice N Easy describes the preferred setup. Having a 2 m filter on the primary pretty much obviates the purpose of the following filter(s) which are there for a reason. It seems intuitive that putting the smallest filter first can create more problems than it solves. One note of potential concern regarding your statement that "The 2 micron Yanmar is hardly ever touched" is that, over time, the chemical bonding agents and filter media itself will break down with no place to go except the injectors. Although it's probably not necessary to change the last filter as often as the primary, it shouldn't be left too long to degrade.
I think Nice N Easy describes the preferred setup. Having a 2 m filter on the primary pretty much obviates the purpose of the following filter(s) which are there for a reason. It seems intuitive that putting the smallest filter first can create more problems than it solves. One note of potential concern regarding your statement that "The 2 micron Yanmar is hardly ever touched" is that, over time, the chemical bonding agents and filter media itself will break down with no place to go except the injectors. Although it's probably not necessary to change the last filter as often as the primary, it shouldn't be left too long to degrade.
Don is correct !!!!!!
That engine filter is nothing but a 'guard' filter; and, should be the SAME uM rated retention as the one immediately preceding it. It is there soley to guard the engine if and when the upstream filters collapse, shed or 'breakthrough' (most of the debris already captured is/can be 'soft' particles that can extrude through a filter if/when the operating differential pressure across the upstream filter sets becomes great). That guard filter is in close proximity to the diaphragm actuated lift pump which will send pressure vectors back/upstream and these small pressure 'surges' will flex the pleats of the guard filter and can (especially if the oil has a lot of emulsified water in it) break by 'fatigue' - the filter media will absorb and then breakdown in long term contact with water. Change the guard filter once yearly --- its an insurance filter.
That engine filter is nothing but a 'guard' filter; and, should be the SAME uM rated retention as the one immediately preceding it. It is there soley to guard the engine if and when the upstream filters collapse, shed or 'breakthrough' (most of the debris already captured is/can be 'soft' particles that can extrude through a filter if/when the operating differential pressure across the upstream filter sets becomes great). That guard filter is in close proximity to the diaphragm actuated lift pump which will send pressure vectors back/upstream and these small pressure 'surges' will flex the pleats of the guard filter and can (especially if the oil has a lot of emulsified water in it) break by 'fatigue' - the filter media will absorb and then breakdown in long term contact with water. Change the guard filter once yearly --- its an insurance filter.
I was taught like Nice N Easy
30 micron in racor near the tank with a 2 micron on the engine. I have used this setup for 5-6 years and no problem The 2 micro has been clean when I change it every year. On another note, I did add the inspection port at the beginning of last year (seabuilt brand). that first cleaning was an eye opener. about 1/4 inch of muck once I wipped down the walls collected in the bottom of the tank. My plan is to perform the ritual of manually cleaning out the tank every 3 years, sooner if the primary racor shows signs of being excessively dirty. tim
30 micron in racor near the tank with a 2 micron on the engine. I have used this setup for 5-6 years and no problem The 2 micro has been clean when I change it every year. On another note, I did add the inspection port at the beginning of last year (seabuilt brand). that first cleaning was an eye opener. about 1/4 inch of muck once I wipped down the walls collected in the bottom of the tank. My plan is to perform the ritual of manually cleaning out the tank every 3 years, sooner if the primary racor shows signs of being excessively dirty. tim
MY BAD
Don, you are absolutely correct, and I just didn't make it plain enough in that post. The 2 micron Yanmar filter is changed on a regular basis. There must be a slipping clutch between brain and fingers. Meant I basically never touch this filter between changes. And I do not change it as regularly as the others. Maybe every other year. But have never, ever had it clog up. And it always comes out looking very clean.
Don, you are absolutely correct, and I just didn't make it plain enough in that post. The 2 micron Yanmar filter is changed on a regular basis. There must be a slipping clutch between brain and fingers. Meant I basically never touch this filter between changes. And I do not change it as regularly as the others. Maybe every other year. But have never, ever had it clog up. And it always comes out looking very clean.
Visualizing filters....
Although the 'clogged' filters in a fuel system are characteristically dark/black, in color, the human eyeball simply cannot SEE particles that are less than approx. 10-15µM, even under 'ideal' conditions. So the moral of this advisement is that a filter may be entirely clogged and have NO external signs and symptoms that its near totally loaded with debris, especially if the particles are clear or transparent, etc. color. Yes, if a filter has the visual appearance of 'full of crud' its probably clogged, but many filters may be partly clogged internally and yet have no external evidence of being clogged. The ONLY precise way to tell if a filter is 'completed' is with a pressure/vacuum gage (on the housing).... or routine changeout based on some 'historical' basis, etc. ..... unless your eyeballs can see better than a microscope.
Although the 'clogged' filters in a fuel system are characteristically dark/black, in color, the human eyeball simply cannot SEE particles that are less than approx. 10-15µM, even under 'ideal' conditions. So the moral of this advisement is that a filter may be entirely clogged and have NO external signs and symptoms that its near totally loaded with debris, especially if the particles are clear or transparent, etc. color. Yes, if a filter has the visual appearance of 'full of crud' its probably clogged, but many filters may be partly clogged internally and yet have no external evidence of being clogged. The ONLY precise way to tell if a filter is 'completed' is with a pressure/vacuum gage (on the housing).... or routine changeout based on some 'historical' basis, etc. ..... unless your eyeballs can see better than a microscope.
Vaccum Gauge would be great!!!!
The 2 micron filters came with the boat and usually are good for a year or longer. If I was having a problem with clogging I would go to a 30 micron filter. But with the 2 microns lasting a year I am not concerned at present. Actually I didn't even know that they were 2 micron until I had to order some more. I have been very lucky with my fuel. Never have more than a drop or two of water and only had crud when I bought fuel at the Grand Mariner at Dog River.
The 2 micron filters came with the boat and usually are good for a year or longer. If I was having a problem with clogging I would go to a 30 micron filter. But with the 2 microns lasting a year I am not concerned at present. Actually I didn't even know that they were 2 micron until I had to order some more. I have been very lucky with my fuel. Never have more than a drop or two of water and only had crud when I bought fuel at the Grand Mariner at Dog River.
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