Managing Fuel Systems

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menzies

Guru
Joined
May 11, 2014
Messages
7,233
Location
USA
Vessel Name
SONAS
Vessel Make
Grand Alaskan 53
This is a thought/question that arose out of the backup thread.

Where you have two or three fuel tanks and are cruising the islands or other remote locations, obviously you fill up in the US before you cross.

When over there, and where you know you will need to take on additional fuel rather than have enough to get there and back, do you run off one tank and keep that topped up, therefore keep one tank secured with US fuel in case you take on bad fuel?

Or just run as usual?
 
We have four tanks. Run off each tank separately. Do not add new fuel to a a tank with old fuel in it.

After taking on new fuel I polish that tank for at least 24 hours. Will switch to the new tank when there is 20 gallons of fuel left in the old tank and will see how it goes. I will then switch back to the old tank - usually at anchor for the generator - until it is empty. Then back to the new fuel.
 
We run as usual and have never taken on bad fuel outside the US. We've taken on old fuel but nothing that has stopped the boat. We always take a sample before it goes in the tank and may use a Baja filter for the first few gallons just to check.

We always pre-screen the fueling facility. Do they move a lot of fuel and have we heard of any complaints? Where local tour boats or sport fishing boats fuel up is usually a good indicator of the fuel quality. Having large capacity fuel tanks allows us to pick where and when we fuel.
 
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We run as usual and have never taken on bad fuel outside the US. We've taken on old fuel but nothing that has stopped the boat. We always take a sample before it goes in the tank and may use a Baja filter for the first few gallons just to check.

We always pre-screen the fueling facility. Do they move a lot of fuel and have we heard of any complaints? Where local tour boats or sport fishing boats fuel up is usually a good indicator of the fuel quality. Having large capacity fuel tanks allows us to pick where and when we fuel.

This is our policy too. If you limit yourself to one tank, then that just means you are buying more and more high priced island and other hinterland fuel. We carry plenty of fuel filters, primary and secondary, but never had to change prematurely. Never polished fuel, either, the high return rate of the Detroits took care of that.
 
Thank you. I got a type of funnel a few years ago by Raycor I think. It has a special screen in it that is suppose to stop water. You have to be careful & never get a spray cleaner etc on sceen or it loses its "magic" properties. Thanks again
 
My boat has 2 fuel tanks, port and starboard. They are plumbed where both the generator and engine draw off the starboard tank. All fuel is taken on the port tank and transferred as needed through a Racor 1000 fuel filter separator to the starboard tank. So all fuel is polished before use. Can also polish the starboard tank if necessary. In the event of a pump failure (also have a spare pump), 2 supply valves can be opened to equalize the tank volumes.

Ted
 
Sounds good. I will have a lot to learn on the boat I'm in process of buying. Twins & generator with 300 gals diesel. I don't know if that's 2 tanks or one. Just passed survey 30 minutes ago. Be on it to bring home to Detroit in less than 2 weeks.
 
Got four fuel tanks. Fill up two each time as more-than-a year's supply isn't needed. Use fuel from one tank at a time. Since they are two on port side and two on starboard side, I switch between a port and starboard tank when there is a noticeable lean of the boat.
 
With 2 tiny 100G each tanks we alternate (to keep down fuel temps) till only 10G remaning in each,

OR till we get to a place with cheap fuel!
 
FF, I've read some engines have a "fuel cooler" that uses raw water to cool the return fuel to tank. Wouldn't that take care of not switching tanks for cooler fuel?
 
FF, I've read some engines have a "fuel cooler" that uses raw water to cool the return fuel to tank. Wouldn't that take care of not switching tanks for cooler fuel?

Many do (mine does). However, in many cases they aren't really needed. Here is an interesting article on it. On my boat, with 2 x 200 gal fuel tanks and an engine that is rarely run anywhere close to its max HP, and that I live in a moderate climate, I'm sure the one on my boat is unnecessary.
 
Had fuel coolers on my Detroits, due to the high return rate of that particular design.
How hard you run the engine doesn't have much effect as the engine temp is regulated by its cooling system.
 
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