I have a new(to me) H27. The gas tank is about 3/4 full with fuel that may have been added 3-4 years ago. Is there any way around not draining the tank? I'm presuming the best way may be from the engine. Thanks. linda
Old diesel fuel
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Do drain the tank
Old fuel can segregate, grow things, and develop nasty things for your fuel system and engine. Exactly how you drain it depends on your set-up. For instance, we have an extra filter and settling bottle in our fuel line, and I could detach the fuel line there. On the other hand, draining at the engine makes sure that you get all of the old fuel out. Be sure to bleed then line after you refill it with fresh fuel. David Lady Lillie
Old fuel can segregate, grow things, and develop nasty things for your fuel system and engine. Exactly how you drain it depends on your set-up. For instance, we have an extra filter and settling bottle in our fuel line, and I could detach the fuel line there. On the other hand, draining at the engine makes sure that you get all of the old fuel out. Be sure to bleed then line after you refill it with fresh fuel. David Lady Lillie
Fuel Treatment
I don't know how your engine's fuel system is set up in the 27 and things get modified over years. This is probably way more than you signed up for, but here's a little bit regarding the age of your fuel, microbial growth, and a potential drain point. I sort of know a little bit about fuel, let me help. Sorry, this is a long one. Absolutely right, micro-organisms actually eat diesel, jet fuel and kerosine - all three of these fuels are from the same cut. Gasolines also grow micro-organisms but they take a lot longer to get established. They remain dormant in the fuel and get there through fuel system vents. They will live and breed in any free water which has settled at the botom of your tank. Kerosine based fuels have suspended water in them and the water falls out of solution with temperature changes and condensation. A slimy algea like substance, black mildew looking spots or strings will form. If you don't have water in your system, you don't have microbial problems, but in order to accomplish that you need a low point drain to get the water out - not practical in boats. They do have oil/water separators with low point drains in them. If safe and practical, this drain should only be opened with the fuel under pressure, thus forcing bad stuff out and not letting air into the system. When fuel comes out and air goes in, the sediment is stirred up, re-introduced into the fuel system, and you got nothing out (assuming the separator is downstream of the pump). You can rig up a tube with a barb and valve at one end to thread into your separator - keep the end of the hose submursed in the bucket/jar. I would recommend draining about a gallon out and putting a sample in a glass jar - do not use plastic buckets as they will develop a static charge and the vapors may explode - yes even diesel. At the bottom of a metal bucket (touch it to a ground on the boat to be safe), about 1/2 full, you can drop in a penny and you should be able to clearly see the president. If you see any sludge or a black tint, get rid of all the fuel in your tank. The fuel in the glass jar should be clean, clear, and bright. If it is a little cloudy or a little dull looking, you may be able to use it. You can treat microbial growth with a product called Biobore. It is like shocking your swimming pool with chlorine and will kill all the bugs, but if you have a bad infestation with slime, strings and all, you will be best suited cleaning the tank. If the sample is just a bit cloudy, no sludge, red, not blackish, drain tank to at 1/4 - 1/3 (I guess if you've gone that far you might as well get rid of all of it), add new fuel to it (full tank)and run it out. Keep adding new fuel as often as you can. It won't hurt to keep an extra filter with you even with known good fuel. Old diesel is much easier to mix up and burn than gasoline. Use your best judgment and dispose of the diesel properly - a heating oil company might take it for free and mix it in. Don't forget to wear gloves and eye protection - be safe and as always, follow all engine manufacturer's recomendations and check with your certified mechanic if you have any doubts.
I don't know how your engine's fuel system is set up in the 27 and things get modified over years. This is probably way more than you signed up for, but here's a little bit regarding the age of your fuel, microbial growth, and a potential drain point. I sort of know a little bit about fuel, let me help. Sorry, this is a long one. Absolutely right, micro-organisms actually eat diesel, jet fuel and kerosine - all three of these fuels are from the same cut. Gasolines also grow micro-organisms but they take a lot longer to get established. They remain dormant in the fuel and get there through fuel system vents. They will live and breed in any free water which has settled at the botom of your tank. Kerosine based fuels have suspended water in them and the water falls out of solution with temperature changes and condensation. A slimy algea like substance, black mildew looking spots or strings will form. If you don't have water in your system, you don't have microbial problems, but in order to accomplish that you need a low point drain to get the water out - not practical in boats. They do have oil/water separators with low point drains in them. If safe and practical, this drain should only be opened with the fuel under pressure, thus forcing bad stuff out and not letting air into the system. When fuel comes out and air goes in, the sediment is stirred up, re-introduced into the fuel system, and you got nothing out (assuming the separator is downstream of the pump). You can rig up a tube with a barb and valve at one end to thread into your separator - keep the end of the hose submursed in the bucket/jar. I would recommend draining about a gallon out and putting a sample in a glass jar - do not use plastic buckets as they will develop a static charge and the vapors may explode - yes even diesel. At the bottom of a metal bucket (touch it to a ground on the boat to be safe), about 1/2 full, you can drop in a penny and you should be able to clearly see the president. If you see any sludge or a black tint, get rid of all the fuel in your tank. The fuel in the glass jar should be clean, clear, and bright. If it is a little cloudy or a little dull looking, you may be able to use it. You can treat microbial growth with a product called Biobore. It is like shocking your swimming pool with chlorine and will kill all the bugs, but if you have a bad infestation with slime, strings and all, you will be best suited cleaning the tank. If the sample is just a bit cloudy, no sludge, red, not blackish, drain tank to at 1/4 - 1/3 (I guess if you've gone that far you might as well get rid of all of it), add new fuel to it (full tank)and run it out. Keep adding new fuel as often as you can. It won't hurt to keep an extra filter with you even with known good fuel. Old diesel is much easier to mix up and burn than gasoline. Use your best judgment and dispose of the diesel properly - a heating oil company might take it for free and mix it in. Don't forget to wear gloves and eye protection - be safe and as always, follow all engine manufacturer's recomendations and check with your certified mechanic if you have any doubts.
OK, Tim, A Question on Gasoline...
...someone I know has about twenty gallons of old gasoline in a seventy-gallon tank. It is about five years old, he says, and he added a preservative several times. Anyway, he's now going to use the boat again, and wonders if just topping off will do the trick. He says he cannot find anyone to pump out and dispose of the old fuel. Comment? RD
...someone I know has about twenty gallons of old gasoline in a seventy-gallon tank. It is about five years old, he says, and he added a preservative several times. Anyway, he's now going to use the boat again, and wonders if just topping off will do the trick. He says he cannot find anyone to pump out and dispose of the old fuel. Comment? RD
Gasoline
Rick, Gasoline is a bit tricky. There are stabilization products that you can buy from auto stores - this mostly helps prevent it from shellacing . I would assume that his tank is vented to atmosphere which means he's lost a lot of the 'light ends' (helps in starting) through vapor loss. Some gasoline goes bad in months, some will last years if in an airtight container. While not recommended due to health reasons, really bad gasoline will smell like paint thinner or shellac - get rid of it because it won't burn and will gum up the system. Gasolines have different additives for different seasons, altitudes, county/state requirements and brand. Call your local waste management company, they usually have a program to get rid of old gasoline, paint, etc. We did in Sacramento. Environmental companies will come and get it but will charge several dollars/gallon. If it were me, if it still smells like gasoline, I tried hard to get rid of it and could'nt - not even using it in my lawnmowers and 2 cycle engines, I'd add another 20 gallons and see if she runs okay. The old stuff is in the fuel system/induction anyway.
Rick, Gasoline is a bit tricky. There are stabilization products that you can buy from auto stores - this mostly helps prevent it from shellacing . I would assume that his tank is vented to atmosphere which means he's lost a lot of the 'light ends' (helps in starting) through vapor loss. Some gasoline goes bad in months, some will last years if in an airtight container. While not recommended due to health reasons, really bad gasoline will smell like paint thinner or shellac - get rid of it because it won't burn and will gum up the system. Gasolines have different additives for different seasons, altitudes, county/state requirements and brand. Call your local waste management company, they usually have a program to get rid of old gasoline, paint, etc. We did in Sacramento. Environmental companies will come and get it but will charge several dollars/gallon. If it were me, if it still smells like gasoline, I tried hard to get rid of it and could'nt - not even using it in my lawnmowers and 2 cycle engines, I'd add another 20 gallons and see if she runs okay. The old stuff is in the fuel system/induction anyway.
what do you do with the old fuel?
Although I have traditionally wintered the boat with a full tank and some biocide/stablizer, by the time she gets splashed again this time around it will be almost two years since it's last "good" steady running. I have decided that it would be best to drain the tank and start with fresh when it eventually hits the water again. But this raises the question, What do I do with 12 gallons of (probably) good diesel fuel? If I had a diesel in my car or knew someone who did that might be an option, but I don't. Any suggestions?
Although I have traditionally wintered the boat with a full tank and some biocide/stablizer, by the time she gets splashed again this time around it will be almost two years since it's last "good" steady running. I have decided that it would be best to drain the tank and start with fresh when it eventually hits the water again. But this raises the question, What do I do with 12 gallons of (probably) good diesel fuel? If I had a diesel in my car or knew someone who did that might be an option, but I don't. Any suggestions?
be legal and environmentally safe
Marine diesel is usually dyed red - don't put it in your car it is very illegal and carries heavy fines (taxes). Any diesel equipment without a plate (tractors, fork lifts, tugs, farm equipment, generators - off road. . . nothing turbine as the dye will void all engine warrantees) will take red dyed diesel. Like I said, and I'm not sure if they'd like the red dye either but try a heating oil jobber (if you live in cold country) - free for them, free for you. I used to get rid of lots of old fuel that way in the Great Lakes. Look in the yellow pages for a local fuel jobber under diesel or gasoline, they should be able to take it or get you in the right direction for your area.
Marine diesel is usually dyed red - don't put it in your car it is very illegal and carries heavy fines (taxes). Any diesel equipment without a plate (tractors, fork lifts, tugs, farm equipment, generators - off road. . . nothing turbine as the dye will void all engine warrantees) will take red dyed diesel. Like I said, and I'm not sure if they'd like the red dye either but try a heating oil jobber (if you live in cold country) - free for them, free for you. I used to get rid of lots of old fuel that way in the Great Lakes. Look in the yellow pages for a local fuel jobber under diesel or gasoline, they should be able to take it or get you in the right direction for your area.
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