Fill Gas Tanks Up Or Not ?

makes1

New Member
Feb 4, 2007
36
Pickwick On Tennessee River
Boat Info
2002 SeaRay 220 Sundeck
Engines
Mercruiser Alpha
Have heard it both ways , Do I fill the tanks full on my Sea Ray 220 Boat & Yamaha FX Cruiser Wave Runner & put Stabil in to avoid condensation or small amount of water going into tank because of the condensation ? Or do I just put Stabil in relevant to the amount of Gas that is in each engine , then top off in spring with fresh gas ? For reference both watercraft are stored right where Ala, MS & TN Meet
 
My vote is to fill them and avoid as much condensation as possible...That's what I've always done, and my water sep filters never had any water in them when I changed them. I do the same with my diesels now.
 
Stabil (marine formula or Startron if ethanol gas) goes in no matter what.

Either completely fill it or completely empty it. Never in between. A little bit impractical to completely empty them with built-in tanks.
 
I used to fill it up, before ethanol, now I run the tank as dry as I can. The logic being that if I'm gonna get separation, make it as little as possible. Of course I use ethanol stabilizer, etc. I'm not sure which is better, though?
 
Of course I use ethanol stabilizer, etc. I'm not sure which is better, though?

I'd say you're wasting your time to try and empty the tank. Between my own boats, my family member's and friend's boats, and the "who knows how many comes through our doors at the shop"... we have yet to see any fuel problems when Startron (for example) is being used. We've seen many problems when it's not being used, but so far so good when it's used on a regular basis.
 
I have 200 gallons sitting till spring
with stabilizer in and vents taped over.
My vote is for fill to the top.
 
My vote is to fill them and avoid as much condensation as possible...That's what I've always done, and my water sep filters never had any water in them when I changed them. I do the same with my diesels now.

+1 Always did the same, always got the same result!
 
Fill them. Because today's money is generally always worth more than tomorrow's money. When you go out for your first ride in the spring you'll have full tanks and will be glad you don't have to fork out hundreds of dollars at that time to fill up the tanks.
 
Fill um...that's what I've alway been told to do....besides winter fuel costs less that summer fuel! Every gas field toy I have will be full with stabil and marina fuel
 
I'd say you're wasting your time to try and empty the tank. Between my own boats, my family member's and friend's boats, and the "who knows how many comes through our doors at the shop"... we have yet to see any fuel problems when Startron (for example) is being used. We've seen many problems when it's not being used, but so far so good when it's used on a regular basis.

+++1 for Startron. I've used it ever since I've had this boat and no issues yet.
 
I always fill them and use Stabil and then go for a short boat ride to allow room for expansion and get the fuel in the system. Never had an issue. My marina does have Valvtec in the fuel. Not sure if the Stabil is necessary. But I do it anyway.
 
I always fill mine too, but leave about 5 gallons worth of room for expansion when the weather gets warmer or else you will have fuel stains coming from the vents, and a ruined boot stripe tape.


This is is exactly what happened to our boat. We topped up, left no room for expansion and got a call from the marina that we were leaking fuel and they had to place socks around the boat to absorb the fuel. Could see the streak left by the fuel running out the vent and peeled/ruined the stripes
 
I run it a low as I can ( i usually get it down to about 20gal and then in the spring use a carter electric pump (for an older 85 ford truck) to pump out the rest of the fuel out in the spring. I made up a fitting to match the fitting that the fuel line goes into the cool fuel unit. I pump it into 5 gallon cans through a canister filter, it tales about an hour to pump both tanks dry. Then I put it in my truck 5 gallon at a time with each full up. It is a pain the a$$ but I had major ethanol problems with my last boat even though I used stabil ethanol treatment on every fill up. The only fix was to drain the tanks completely and start over. By doing this every year I know I have the least chance of ethanol related fuel problems because I start with 100% fresh fuel each spring.
 
Maybe I can get some more feedback for the 2014 winterization. Have 100-gallon tank. Gauge currently showing between 1/4 and 1/2. Do I fill or is it good? Regardless, do I put any fuel treatment in too? Cost isn't an issue as our Harbormaster keeps the price pretty constant based off his price. Even though we are at some really good prices for our POV's, the boat is still costing me the same!
 
2014 compared to 2013 (when this thread was written) makes no difference. All of the information is the same and we'd really only be repeating ourselves. In fact, I think that's what most of us end up doing every year regarding questions like this, and winterization questions in general... repeating ourselves.
 
I have always just treated what was in the tank when I winterized... but I don't have to deal with wild temp swings... its always 64* in the caves where Little Bit is stored... no problems.

 
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