Winterization - full gas tank or not?

This may be a silly question to you folks who have been boating for years, but this may have been my last weekend on the water with my new-to-me 86 Bass Boat (18' Bayliner with 125 Force outboard)

This week I am planning to fog the motor, lower it down to make sure all water is drained, pull the batteries and get her ready for the winter.

I now have about 1/4 tank of gas (25 gallon inboard tank). I will add stabil to it, but I am wondering if I leave it with the 1/4 tank of gas for the winter or fill it up before it gets parked.

If I leave it at 1/4 tank, then in spring 3/4 of the gas will be fresh first time out. If I fill it before it snows, then it seems there would be less opportunity for condensation.

What is the best thing to do for winter? It will be parked outside, but covered. I might add that I stay far far away from Ethanol, and try to use only NON-Ethanol in everything I own.

Thanks for your help! Any other pre-winter suggestions would be appreciated!

Re: Winterization - full gas tank or not?

good question! it has been debated before. i personally like to store them full, but others will say it doesnt matter. in my location, there is so many temperature ups'n'downs during the winter , that condesation plays a big factor, as well as corrosion. if you have a ss tank, and a water seperater/filter, a partial tank with stabilizer might be ok. jmo

Re: Winterization - full gas tank or not?

Full to the top with a double dose of StaBil Marine. Just like the owners manual says. I believe that Chevron and Shell give the same advice now.

Re: Winterization - full gas tank or not?

Store full. If it is not full, it tends to create more condensation. At least that is what I have always done. I also run the tank almost empty, then fill up to the top with non-ethonal gas. Again, so it doesnt create as much condensation.

I also do not have to put it up very long. And typically take it out several times during the winter, so I have no real experiance with leaving it sit all winter.

Re: Winterization - full gas tank or not?

Thank you all for the advise. Will fill tank and double up on the Sta-Bil.

Boat will get put away in a couple weeks (mid october) and most likely not see water again till March or April.

Iowa winters are hard, cold and waaaay to long!

Re: Winterization - full gas tank or not?

mbhoag said:

Thank you all for the advise. Will fill tank and double up on the Sta-Bil.

Boat will get put away in a couple weeks (mid october) and most likely not see water again till March or April.

Iowa winters are hard, cold and waaaay to long!

Click to expand...

You said it brother, but Minnesota has Iowa beat when comes to a long miserable winter though.

Re: Winterization - full gas tank or not?

mbhoag said:

Thank you all for the advise. Will fill tank and double up on the Sta-Bil.

Boat will get put away in a couple weeks (mid october) and most likely not see water again till March or April.

Iowa winters are hard, cold and waaaay to long!

Click to expand...

Howdy,


A discussion of fuel tank condensation would not be complete without adding a little fact to the testimonials.

I used to think the same thing because it's even more important with aircraft fuel tanks since they're usually DIRECTLY exposed to cold and heat outside.
However, I noticed that aircraft fuel tanks didn't seem to make water on their own.

I've ALWAYS stored my boat with a fuel level of 1/4 or less and NEVER found any water in the tank (and I've looked)

The marine surveyor in the following took the time to prove it ....

http://www.yachtsurvey.com/myth_of_condensation_in_fuel_tanks.htm


If you don't want to read the article all the way thru,

Leaking Fill Caps
By far the most common cause of contaminated boat tanks are deck fill caps that leak. Most of these things are stupidly mounted flat on decks which may puddle with water. The cap has a tiny little O-ring that is supposed to seal and keep water out. DOES IT? I wouldn't depend on one of these things unless I could prove that it doesn't leak. Check the condition of the o-ring and weather it is sealing.

Click to expand...

I suppose I am going to be the "lone disagree'er"

I NEVER store with my fuel tank full....in either the boat or the airplane, AND I never get any water when I drain samples.....




Oh, and by the way, if you're going to let it sit outside in the weather, ensure that you store the engine "DOWN" so water doesn't pool anyplace in the lower unit.

Remove your battery and put it in the garage. Use a good "pulse-type" trickle charger to maintain it for the several months you won't use it ....(AND don't worry about putting it on the concrete floor.....That old-wives-tail is also BS !!) Just thoroughly clean the top of the battery with a little bicarb-soda and finish washing with a little detergent, then rinse and dry it completely,


ymmv






Rick

Re: Winterization - full gas tank or not?

I have a 94 gallon tank and store whatever is left in the tank after the last outing. Sometime 80 gallons, sometime 20 gallons. Just add the recommended amount of stabilzer and forget about it until it comes out of storage in the Spring. Never had any problems with water.

Re: Winterization - full gas tank or not?

Thank you Rick, interesting article! Definately gives me more to ponder.

I will however be storing with engine down, and batteries removed. They will be stored in the basement, not the garage.. and on a 'battery minder' unit.

The boat will be outside, but will have a full cover over it, reducing the chances of snow & water getting to the tank or anything else.

Thanks!

Re: Winterization - full gas tank or not?

I usually cycle the engine up and down a few times before leaving it down, you'll see how much water comes out when you do this.

I'm also in the camp of storing with whatever is left in the tank, I double treat with a good Ethanol treatment, usually Star Tron, and run it through the engine well also so you have treated fuel in your engine throughout the winter. Never had an issue with any moisture in the fuel even with ethanol and that's with a 200 gallons tank sometimes left with 20 gallons in all winter.