Fuel Tank Winterizing

[daniel123]

I live above the Mason-Dixon Line and it's time to put the (new-to-me) boat to bed until spring and I want to do it right. I've got about half a tank/25 gallons of 89 octane/10% Ethanol fuel in my Osprey's 50 gallon below-deck tank that was treated with StarTron when I filled it in mid-August. I won't use the boat again until I head to Florida in late March and am concerned that it will separate and deteriorate between now and then. I tried to siphon out the remaining fuel, removing the fuel line from the outboard, dropping it over the transom below the level of the hull/tank, and using the primer bulb and my thumb to create suction but it doesn't work (Because as it leads aft, the line rises higher than the fuel tank?). I'm curious about how other AS owners handle off-season fuel issues and any advice that can be offered. If I can't drain the tank, I'm tempted to top it off with high octane (albeit with Ethanol, as there are no gas stations in my area that offer non-Ethanol fuel) gas, treat it with StarTron, and leave it until spring. Advice?

[slvrlng]

Sounds like you need to go for a boat ride!!!

Sorry, I just had to say that!

I would at least try to get the old fuel out and then refill all the way and treat the "new" gas.

You can get an inexpensive fuel pump (like off a chevy pickup) at the parts store. Connect the fuel line from motor and then run the electric connections to some looong leads to a battery at least 20 feet away. Pump the primer bulb and make your connections.

Where are you located?  Check out  www.pure-gas.org maybe there is one you didn't know about.

[Capt. Bob]

My approach is opposite of the standard. I drain the fuel out as much as possible. I have two pickups on my tank and use one for a gravity feed drain. If your drain line is long enough to end at a lower point than the bottom of your tank, the fuel will drain once the flow starts. The line rising above the fuel tank is not a factor in why you can't drain the fuel. Liquid will rise in that elevated section of hose till it equals the outside pressure (think the atm pressure) in the tank. Sailors use this principle all the time in gauging the weather (think barometer).  Gravity then becomes your friend and will pull the fuel through the remainder of the line. That down force of the fuel flow will cause an additional loss of pressure (minimal) thus aiding the push of the outside air. You should be able to drain your tank once you get the fuel to flow. A squeeze bulb (primer bulb) works well. Don't expect the fuel to flow at a high rate  so and extra beer or two never hurts.

 The fuel I remove goes into my motorcycle or better yet, my son's pickup. Now with the small amount of fuel left in the tank plus any condensate (think water) that collects in the empty tank, I add fresh fuel (5 gal) and a dryer (aka ethanol) in the spring. I drain once more and burn that mess in the John Deere. That way I have a relatively clean tank with a minimum of effort to fill with fresh fuel. I have done this since installing the new tank in 2010 and it has been successful so far. I will not top off a tank again.

As Lewis stated, you could just run the fuel out and have some fun at the same time. This works for me. I don't waste any fuel and my issues with ethanol appear to be under control as of now.

As always, your mileage may vary..... literally.

[daniel123]

If I can get tank empty why would you recommend re-filling it? Won't that newer fuel just go bad between now and next spring? Going that route, why not just top off what is in there now and treat? If I can empty the tank, my plan is to just leave it empty until next spring. Then agian, the opens it upforcondensation, but I figure that's not as bad as finding rotten fuel next season.

As for draining, I don't have a separate gravity drain outlet. Do I pump out using a pipe/tubing inserted in the fuel fill hole?

Thanks guys!

[wingtime]

I think he meant he puts a small amount of fuel in it in the spring then drains that out to get any condensation that may have gotten in there during the winter.

[slvrlng]

Hook the fuel line from the primer bulb to the motor to the exterior fuel pump. Then connect to battery. Of course connect the pump up first then the battery side.

My two cents are that up north where it truly gets cold and stays that way is that if the tank is empty it exaggerates the condensation problem because of the cold. The ethanol in any residual gas in the tank will draw moisture out of the air and then separate. If it is filled all the way and treated and still separates then sue stabil. By filling you are reducing the air to gas surface area.

Where do you live?

[Capt. Bob]

If I can get tank empty why would you recommend re-filling it? Won't that newer fuel just go bad between now and next spring? Going that route, why not just top off what is in there now and treat? If I can empty the tank, my plan is to just leave it empty until next spring. Then agian, the opens it upforcondensation, but I figure that's not as bad as finding rotten fuel next season.

As Wing stated, I add a splash (for you NASCAR fans) at the start of the season and then drain again to remove that fuel which mixes with the dryer and all the water Lewis' is saying gets in the tank. I do not refill the tank. That's where the difference in method/opinions lie.

As for draining, I don't have a separate gravity drain outlet. Do I pump out using a pipe/tubing inserted in the fuel fill hole?

I drained my CCP tank using the pickup tube that attached to the motor. There was not a separate drain tube.

My WAC tank was built with a separate pickup tube to avoid having to disconnect my main fuel line from the motor.

Point is, it will work either way. You may however be experiencing a problem draining due to the anti-siphon valve that may be present on your tank.

[Double Trouble]

I am up in NY and winterize my boat for 4 1/2 months. I use 10% ethanol because thats all we can get up here. I use sta-bil all year long as do most guys in my marina, for the winter layup we  triple dose what ever fuel is in the tank been doing this for quite a few years now, come spring I change my plugs and fuel filters and go fishing with no problems. The problem with condinsation seems to happen when temps constantly change from cold to warm and back again which doesnt happen in winter up here. I used to have nightmares about the ethanol problem now I sleep very well.

[daniel123]

Thanks for all the advice, guys. To answer one question, I'm in Columbus, Ohio. Winter temps do fluctuate here more than NY, so I am thinking I should just top it off and overdose it with StarTron.

What's the chance a 1998 Osprey fuel tank was fitted with an anti-siphon valve? If so, does that means if I do ever decide to drain the tank that I must go straight to the tank via the fuel filler hole?

Dan

[seabob4]

Thanks for all the advice, guys. To answer one question, I'm in Columbus, Ohio. Winter temps do fluctuate here more than NY, so I am thinking I should just top it off and overdose it with StarTron.

What's the chance a 1998 Osprey fuel tank was fitted with an anti-siphon valve? If so, does that means if I do ever decide to drain the tank that I must go straight to the tank via the fuel filler hole?

Dan

Very GOOD chance it has one.  Fuel tank manufacturers don't know if the tank they supply a builder is going to be used on an O/B powered boat (not required), or an I/O or I/B powered boat (required)...so the tank is shipped with an anti-siphon pickup.

As many have done here, swap out the anti-siphon for a Sierra straight barb (about $4 at Worst) and be done with it...

[Capt. Bob]

What's the chance a 1998 Osprey fuel tank was fitted with an anti-siphon valve? If so, does that means if I do ever decide to drain the tank that I must go straight to the tank via the fuel filler hole?

Judging from posts/threads on this Forum concerning anti-siphon valves, I'd think you may have a good chance of having one. Still, that's just a guess without removing the pickup connection elbow and looking. The pump idea would certainly overcome a functioning A-S valve so that's a viable alternative if/when you decide to drain.

[daniel123]

As usual, that's great info, guys. How/where do I access the area to remove and replace the A/S with the Sierra fitting? Are there any downsides to removing the A/S feature?

Also, I found an auto-siphon hose in the most recent Harbor Freight ad that is made with copper tubing and sounds a lot like a gravity-type siphon device that has been recommended (either here on in a similar boat winterizing post I read) for draining boat tanks via the fuel-fill hole. It's under $10. Any thoughts?

[kraw2]

If you're running outboards you don't need it..

I know I have shown this before but it's cheap to make and you can draw from the fuel line or remove the sender and use a long hose and draw fron the bottom of the tank. It's just an automotive fuel pump pushing fuel thru a fuel/water serperator and out to wherever you want the fuel to go.

[daniel123]

Sorry it's not clear to me, but if I'm running an outboard, I don't need what? (a-s valve, Sierra barb fitting or the siphon pump?)

And thanks for showing the power drain set-up.

Instead of removing the sending unit access (mine's rusted in place until I get around to replacing the sender), can't I just feed a hose down to the tank via the fuel filler hole to siphon or use a pump to drain the tank?

Dan

[Capt. Bob]

Sorry it's not clear to me, but if I'm running an outboard, I don't need what? (a-s valve, Sierra barb fitting or the siphon pump?)

I'm assuming he means the A-S valve.
The barb would be used to replace the valve on your pickup, if you have a valve and choose to remove it.
The pump is just another way (option) to drain the tank in lieu of the siphon method.

Instead of removing the sending unit access (mine's rusted in place until I get around to replacing the sender), can't I just feed a hose down to the tank via the fuel filler hole to siphon or use a pump to drain the tank?

Yes you could but....
I would suggest you keep the tank (boat) as level as possible.
Use a drain hose that is flexible enough to traverse the fill hose bend at the tank neck fitting (this may or may not be easy, never tried myself). Logic would dictate that a smaller diameter hose would be better suited for this task but you then give up transfer (drain) speed. Remember the extra beer.
The only way you will have to determine if the hose has hit the bottom is by feel. It may be impacting the side or a baffle before settling on the bottom. Hit or miss.

Good luck.