boat gasoline

I just took my boat in to be winterized and my machanic told me that I shouldn’t run gas with ethanol. He also said to use gasoline with the highest level of octane possible. I just wanted to know if others agree. Also, he said not to have a full tank of gas during winter storage even if there is stable in it. Any confirmation is appreciated.

Run EXACTLY what the owner’s manual suggests. In my case, with a 175 Yamaha HPDI, that’s 88 octane. Nothing special. My guess is there’s lots of guys spending extra money on premium when they don’t need to and without any benefit to the motor regarding performance.

I was told a long time ago not to use gas with ethanol in it so i never have What was the reason for the full tank?

A full tank keeps the gas mixed… in case you have any ethanol at all in it. Also helps to keep the lines completely full of gas so that water can’t travel along them. The best way is to store your boat with a full tank, always. Also, drop something like sea foam into it. Helps a lot to keep the gas from separating.

I have heard some say that ethanol eats gaskets. Other’s say in newer motors it’s fine. I’ve seen this argued out both ways with intelligent folks on both sides, which has left me with the answer James gives. Do what the manufacturer suggest.

I guess the reason for a full tank of gas was to stop moisture over winter . Maybe this is true with a metal tank [ Old Wives Tales ] I don’t know . I guess my 96′ Alumacraft has a plastic tank which I didn’t know .

On older motors, Ethanol will eat rubber gaskets and seals. This is bad. On newer motors, they have improved the materials (for the most part) that are used in the manufacture and assembly such that ethanol will likely cause no problems if you run it regularly.

Now, the reason why that last part is bold, and the reason why you should never, ever store your boat with ethanol in the tank & fuel line/carb is because ethanol will absorb water from the air around it…. Worth repeating: Ethanol sucks moisture out of the air and holds it.

If you buy a tank and run through it in a week or two, you will never have a problem. The longer it sits, the more water content it contains, and the less effective it is.

Home science experiment: Take an accurate measuring device, fill it half full with ‘regular’ gasoline (a). Now dump in some water (b)… what does the volume read? It reads (a+b).

Do the same experiment with ethanol, and the result will not yield the same volume, because a portion of the water is absorbed; molecules -n- stuff.

I always store with a full tank w/ stabilizer. Keeps the metal tanks from rusting. An important lesson I learned after inheriting a 1978 Suzuki GS-1000 from a friend who moved to MN. Tank was dry and completely rotten with rust. No shop in town would even touch it for repair.