Draining the fuel tank

[Blue Pearl Captain]

I've read in the manual that draining the fuel tank is regular maintenance. Is this necessary if you use a fuel strainer?
If so, where is the valve, how do you access it, what size hose do I need?
Could someone walk me through the process on my 1993 Hunter 27 with a Yanmar diesel 1GM10?
I assume I should run the motor until I "think" it's near empty (12 gal) before diving into this.
If it wasn't for you guys my learning curve would be flat!
Thank you.

 

[capejt]

I may be wrong here, but on my H33, and as I believe, ALL Hunters don't have a drain valve. Especially like the one shown in the Yanmar manuals. Most likely, you're going to end up siphoning or pumping it out. Therefore, your inclination to "run it dry" or at least close is a good one. It means less to pump and store.
Also, if you consider "regular" maintenance as every year, relax, just throw some stabilizer and anti-algae stuff in the tank in fall.

 

[Sailgunner]

To appropriate clean your tank you need access to it and an inspection port. I do everything to keep the fuel clean but still "clean out" my tank each year. With an inspection port you can get a rag in the tank and wipe out the black stuff that is in the bottom of the tank. No matter what anyone else tells you there will be black stuff in the bottom of your tank. Now you can go for years and not worry about it, especially if you are on a lake and never let the tank get low. But if you get in heavy seas and low on fuel that back stuff can get sucked into the filters and clog them up. Then the engine shuts down when you need it the most.

 

[jdhohmann]

I have owned boats for a lot of years and I have never cleaned out my
fuel tanks... I would say that if you use clean fuel and change your filters fairly regularlly, you should not have to clean out your tank. In fact, with my present sailboat, hunter 40, with 2 40 gallon tanks, they have never been cleaned out...:dance:

 

[Blue Pearl Captain]

I may be wrong here, but on my H33, and as I believe, ALL Hunters don't have a drain valve. Especially like the one shown in the Yanmar manuals. Most likely, you're going to end up siphoning or pumping it out. Therefore, your inclination to "run it dry" or at least close is a good one. It means less to pump and store.
Also, if you consider "regular" maintenance as every year, relax, just throw some stabilizer and anti-algae stuff in the tank in fall.

Don't know about all Hunters but at least 2 of us don't have a drain valve!
Thanks.

 

[Blue Pearl Captain]

I have owned boats for a lot of years and I have never cleaned out my
fuel tanks... I would say that if you use clean fuel and change your filters fairly regularlly, you should not have to clean out your tank. In fact, with my present sailboat, hunter 40, with 2 40 gallon tanks, they have never been cleaned out...:dance:

Thanks. I'm on board with that....

 

[Blue Pearl Captain]

To appropriate clean your tank you need access to it and an inspection port. I do everything to keep the fuel clean but still "clean out" my tank each year. With an inspection port you can get a rag in the tank and wipe out the black stuff that is in the bottom of the tank. No matter what anyone else tells you there will be black stuff in the bottom of your tank. Now you can go for years and not worry about it, especially if you are on a lake and never let the tank get low. But if you get in heavy seas and low on fuel that back stuff can get sucked into the filters and clog them up. Then the engine shuts down when you need it the most.

Fortunately I'm on a lake!
Thank you.

 

[Benny17441]

One of the characteristics of diesel fuel is that it is good breeding grounds for bacteria. You pick them up by the millions every time you fuel the boat. Now they also die in large numbers and their carcasses fall to the bottom of the tank and clump together to form that black crust. This usually do not pose a problem until you go out to sea and hit a patch of high waves and disturbed waters where the motion will dislodge the bacteria from the bottom into your primary/water separator filter clogging it and starving the engine for fuel. Now cleaning the tank is a pain in the butt so you would need to make a decision on whether to clean or not based on your type of sailing. Being on a lake I would think that you would rarely encounter the high seas I'm talking about with waves over 5' so you may choose not to clean but to treat. You will need to add anti-bacterial additives to the fuel and replace the filters more frequently but avoid the job of installing an inspection port and cleaning the tank. The engine can only remove so much fuel before it starts sucking air and dies. That is why when we talk about fuel tank capacity we also usually refer "usable tank capacity". For a 12 gallon tank you may still have 1/2 gallon left after the engine dies and that will be in calm water with no boat motion. This fuel would have to be pumped out or soaked up or drained through the tank valve. The great majority of boaters do not clean the fuel tank and choose to treat the fuel instead. There is an alternative and a process whereby fuel is polished by pumping it out and passing it through filters before returning it to the tank. This cleans the fuel and can help remove the loose particles in the bottom . The people that have the equipment for doing this usually charge around $350 for a small tank. I have suffered the consequences of having to change clogged filters at sea but the occurrence has been infrequent and my choice has been to use additives. I have also a couple of times allowed the tank to get low and take the boat out to let the fuel slosh around inside the tank and then pump it dry before filling it up with new fuel. I hope this gives you basic alternatives.

 

[Blue Pearl Captain]

One of the characteristics of diesel fuel is that it is good breeding grounds for bacteria. You pick them up by the millions every time you fuel the boat. Now they also die in large numbers and their carcasses fall to the bottom of the tank and clump together to form that black crust. This usually do not pose a problem until you go out to sea and hit a patch of high waves and disturbed waters where the motion will dislodge the bacteria from the bottom into your primary/water separator filter clogging it and starving the engine for fuel. Now cleaning the tank is a pain in the butt so you would need to make a decision on whether to clean or not based on your type of sailing. Being on a lake I would think that you would rarely encounter the high seas I'm talking about with waves over 5' so you may choose not to clean but to treat. You will need to add anti-bacterial additives to the fuel and replace the filters more frequently but avoid the job of installing an inspection port and cleaning the tank. The engine can only remove so much fuel before it starts sucking air and dies. That is why when we talk about fuel tank capacity we also usually refer "usable tank capacity". For a 12 gallon tank you may still have 1/2 gallon left after the engine dies and that will be in calm water with no boat motion. This fuel would have to be pumped out or soaked up or drained through the tank valve. The great majority of boaters do not clean the fuel tank and choose to treat the fuel instead. There is an alternative and a process whereby fuel is polished by pumping it out and passing it through filters before returning it to the tank. This cleans the fuel and can help remove the loose particles in the bottom . The people that have the equipment for doing this usually charge around $350 for a small tank. I have suffered the consequences of having to change clogged filters at sea but the occurrence has been infrequent and my choice has been to use additives. I have also a couple of times allowed the tank to get low and take the boat out to let the fuel slosh around inside the tank and then pump it dry before filling it up with new fuel. I hope this gives you basic alternatives.

Admireably so! Thanks, Benny. The likelihood of 5+ ft waves on our lake is nil. I think I'll put the time and money into regular filter changes and dream of high seas!
I did sail 36 hours of gale force squalls in the Grenadines last summer on a chartered Jeanneau 50 DS. Fortunately it had a clean tank and clean fuel

 

[Stu Jackson]

Benny's right, good overall evaluation. YOU have to make the choices for your boat. You should also check to see if there is a screen in the fuel pickup tube inside the tank. Many builders put them in, thinking it would help - it doesn't, just makes a place for stuff to clog up. Big time. IMHO, fuel polishing has more hype, in some cases, than validity, 'cuz if the bottom of your tank is filthy, fuel polishing won't help, you need to pull the tank and either clean it or replace it.

 

[Blue Pearl Captain]

Benny's right, good overall evaluation. YOU have to make the choices for your boat. You should also check to see if there is a screen in the fuel pickup tube inside the tank. Many builders put them in, thinking it would help - it doesn't, just makes a place for stuff to clog up. Big time. IMHO, fuel polishing has more hype, in some cases, than validity, 'cuz if the bottom of your tank is filthy, fuel polishing won't help, you need to pull the tank and either clean it or replace it.

Super! I do put in an additive with each fueling which is ususally about 5-6 gallons at a time.

 

[Kh3412]

I have a 1989 model 27 ft. that is close to yours. No drain and hard to get to to work on. In the process of cutting hatches in the bulkhead to access the batteries on the starboard and hoses and tanks on the port. Starboard is in and it made it so much easier to install and attach the batteries. The tank is held in with two nylon straps and with both hatches should be easy to remove and service. As a plus was able to clean the fuel gauge on top of the tank and may be able to read it.

 

[Blue Pearl Captain]

I have a 1989 model 27 ft. that is close to yours. No drain and hard to get to to work on. In the process of cutting hatches in the bulkhead to access the batteries on the starboard and hoses and tanks on the port. Starboard is in and it made it so much easier to install and attach the batteries. The tank is held in with two nylon straps and with both hatches should be easy to remove and service. As a plus was able to clean the fuel gauge on top of the tank and may be able to read it.

Gauge? What gauge????

 

[wufibugs]

If you do a search you will see how some folks have added a cleanout/inspection port to their tanks.

 

[Picflight]

Try pumping the fuel through filters and back into the tank.

 

[Kh3412]

The top of the tank has a mechanical gauge that can be seen from the port rear seat

 

[Kh3412]

Pictures to come when at boat

 

[Steve Dion]

Yes, a periodic cleaning of the fuel tank may be in order. I have a dual filter system on my boat for just this purpose. I changed one of the filters this weekend only to find the mess in the attached photo.

 

[Picflight]

Let the filters do the clean up and keep replacing the filters.

 

[Blue Pearl Captain]

Let the filters do the clean up and keep replacing the filters.

Sounds good to me! Thx.