So my usage has been all over. Some years due to child injury zero use. Others maybe leave the dock once or twice. Never really had a fuel issue. I do start the boat and run it every 2-3 weeks. I use valvetec fuel from the marina. Use stabil before winter layup. Keep tank at least 3/4 full over winter as well.

 

Run the fuel tank down to the point where you need to refuel. Then buy enough fuel to get you back to your slip and for a return refueling trip. Fuel up weekly so systems get used. Buy alcohol free fuel and treat it with Stabil. I’m using two year old gasoline in my snowblower with absolutely no issues. Gasoline is such a small part of the overall cost of boating you could save money by reducing the cruising part of the season and putz around locally. If you did that you could fill up and probably go for weeks without buying fuel and still use the boat and its systems. If all else fails stay on top of your fuel filters.

 

Run the fuel tank down to the point where you need to refuel. Then buy enough fuel to get you back to your slip and for a return refueling trip. Fuel up weekly so systems get used. Buy alcohol free fuel and treat it with Stabil. I’m using two year gasoline in my snowblower with absolutely not issues. Gasoline is such a small part of the overall cost of boating you could save money by reducing the cruising part of the season and putz around locally. If you did that you could fill up and probably go for weeks without buying fuel and still use the boat and its systems. If all else fails stay on top of your fuel filters.

@MonacoMike This is the way to keep things working. Use the boat locally and the tanks low and fill a little bit often. Run the generator the more the better, under load. I have done this exact thing over the years, use twice the amount of Star Tron fuel additive, not Stabil. Change the fuel filters mid way through the season and at the end of the season.

@ttmott Tom's point is very valid and condensation does occur, but full tanks sitting at the dock for the entire season will do more harm then good. Absolutely fill the boat at the end of the season for winter storage. That's when the condensation will be at it's worst, the wide temperature range fall and spring brings.

The thing to remember is nothing likes to sit, the best running car let sit for a few years will turn to crap in a few short years.

 

Yeah, I am using fuel in my law mower I purchased in 2020, still runs like a charm. Last boat I purchased had been sitting for a very long time, 4+ years I think, when it was purchased from the owner I purchased it from. He had to replace pretty much everything from the fuel tank (not the tanks themselves) to the injectors, and in between. I reaped the benefits of that.

If it's going to be a permanent floating condo why not just pull the engines and tanks? I agree with @sbw1, though I am honestly not sure if Stabil does anything, or if it's just a feel good. I've read idling at the dock too often is bad for engines so that may do more harm than good.

 

Ensure the fuel fill caps have new o-rings and there's no way rain water can get in the vents...

 

I'll depart a bit from @sbw1 in that always try to keep you fuel tanks full. All fuel tanks "breath" and it's that breathing that brings in the moist atmosphere; reducing the volume reduces the moisture getting in the tank.
Secondly, for marine engines that don't run often the fuel needs to be treated so varnish, corrosion, and water are kept at bay as well as maintaining the gasoline's chemical composition. I've only a 40 gallon tank in the runabout but I can say I've never had a single problem related to fuel. For treatment I put in Yamalube Stabilizer and fuel additive every time fuel is added or Stabil if I can't get the Yamalube product. I purchase from Amazon in a case of 12.
As an edit anything made by Biobor is good.

 

@sbw1 and @ttmott both offered perspectives on leaving the tanks full or empty.

My addition is the fact this discussion/debate was going on a long long time ago when I was young growing up on a farm. Was typical once fall tillage was done tractors were parked until sometime in the spring. Most of the winter was too cold to even start them (if anyone wanted to). Stored in sheds with no electricity to plug in a block heater.

I remember growing up every fall around the table at the local restaurant the debate among farmers on whether to empty the tank in the fall or fill the tank in the fall.

 

I hope no one knows the answer to this ….it’s just wrong

 

My father had the 80 gallon fuel tank pumped out last fall, a combination of issues allowed water to get into the tank.

The pump out driver offered this advice
If it’s ethanol fuel, leave the tank as low as possible.
If it’s non ethanol, fill it up for long term storage.

 

This is exactly what Mercury recommends:

Since we have ethanol I store low and stabilize.

-Kevin

 

Keep in mind this is for Gas boats with ethanol - NOT diesels.

-Kevin

 

Mike………………

My suggestion is to get in the helm seat, fire it up, and go have dinner in Michigan City or St Joe in total comfort with the gen running the A/C or Heat. Spend the night even! Cruise home in the morning and enjoy the day on the other boat.

We will take ours too!

 

This came up,recently in a conversation about fuel costs and boat usage with high gas prices and all. If one wanted to use their boat as a floating condo what would need to be done, particularly to the gasoline fuel systems?

With Covid and the purchase of a bigger day boat I did not use the boat that much in 2020 and had a boat load of fuel issues to deal with last year. How does one avoid those types of issues while not using the boat?

Would an hour or so of running at the dock per week keep things clean? What about the generator? What should be done to keep things running great while in the water but not getting much use?

If it's just the price of fuel that is the issue I'd recommend just using it less but still use it. If fuel price doubles then just run the boat half as much.

 

I would take the motors out and sell them…. use the money for slip fees next year

oh oh and sell the steering wheel $300 easy money if you sell it here

 

No motors would violate my slip lease, but maybe the wheel. LOL

 

Thanks all for the input…

 

Even mine ?

 

I will wade in a bit. You are talking about leaving the boat in the slip. And like we have up in Ontario, you have hot humid days and cooler nights during summer. So leaving your tanks not full will allow a lot of "breathing" in and out of extremely humid saturated air. Think of all the dew on the boat in the AM. The air drawn into the tank is going to have that level of humidity and condensation that will build up over the summer and sink to the bottom. I know the winterize debate on full vs empty, but that is not with the fuel vent sitting 2ft above water in summer.

So for that reason, leave the tanks full and use Startron or similar that has some degree of water emulsifier as well as stabilized, and run it as often as you can to pull some of that moisture laden fuel out. Make sure you install a water separator on the fuel line too. Sierra makes some inexpensive ones that have good capacity.

 

So is this thread question better now than in February when I posted it? Some here did not seem to believe what many here saw coming…