If you don’t have a fuel/water separator on your boat you may want to reconsider. I am going over my boat from stem to stern (pun intended) trying to get ready for a trip to the Keys in a week or so. I changed the filter on my fuel/water separator and when I poured out what was in the old filter, this is what I saw. Yuck. Thank goodness the filter caught whatever this is (water?) Not anything to do with ethanol as I quit using gas with ethanol 5 years ago. Anyway, I thought I’d share.
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“Apathy is the Glove into Which Evil Slips It’s Hand”.
I’ve heard mechanics say varnish from old gas, all I can add for you.
Maybe happened during winter months?
“The big one’s still swimming, let’s go.”
They are imperative on a boat in my opinion. It helps if you get one with the sight bowl. That way you can keep an eye on what is being separated, and also drain off the junk. I got a bad fill up of gas last summer and the filter probably removed two cups worth of junk at least from the incoming gas. Motor never skipped a beat. Good thing to change every season whether you think you need to or not.
2000 SeaPro 180CC w/ Yammy 115 2 stroke
1966 13’ Boston Whaler w/ Merc 25 4 stroke “Flatty”
www.ralphphillipsinshore.com
Do you store your boat outdoors? If so the tank will suck in humid air and then condensate inside the tank from sitting outside.
“Wailord”
1979 17’ Montauk
90 Johnson
Wilderness Ride 115
Phase seperation of gas and it sucking up moisture - that is ethanol for you 
!! Drain tank and change all filters !!
Only use non-ethanol gas !!!
It’s always a good idea to keep your fuel separated from your water 
Why in the world would you not?
Capt. Larry Teuton
Swamp Worshiper