bad gas?

[brttkrz]

So today i am at the dock and turn the key to start my boat ( 95 sport nautique with the GT-40) and all it does is turns over for a while but won't start. I push the reset buttons at the back of the boat thinking maybe the one to the fuel system blew the breaker. After a while of messing with it making sure wires are connected and breakers aren't blown it started up. I back away from the dock and then put it in forward and it died and would not start again so had to swim it back to the dock. Pull it out of the water and then just for the fun of it i thought i'll try and start it again and it started with no problem and then i shut it off right away. Tried it again and it started again so I put back in the water. When it was in the water it would not start again, just kept turning over like it wasn't getting gas. We pulled it out and took everything apart to get at the gas tank and fuel lines. Pulled the main line to the motor off and checked if it was getting fuel when we turned it over. Did not get anything to flow (maybe it is because it needs to be a closed system?) Then we took the fuel filter off and drained the fuel out of it. Checked the volts to the fuel pump in the gas tank and we turned it over and it was 1.3 volts (is this normal?). Thought it was maybe the fuel pump at were going to call it a day. Put all the lines back together and just for the fun of it tried starting it again a couple times and then it started right up and ran. It has a tank full of 89 octane 10% ethanol and 91 octane 10% ethanol mixed 50/50. I thought the 91 octane had no ethanol but turns out when i rechecked at the station it was ethanol blend. Thought it may be bad fuel so ran and got 2 bottles of sea foam and put them in the gas tank. Put the boat in the water and it started but ran a little bit rough at first but then got better. Ran fine the rest of the day. Could this be due to 10% ethanol gas sitting in the tank for 2 weeks and causing issues or water in the fuel? I will replace the fuel filter but do I need to worry about the fuel pump?
Thanks

[LOWbook]

I would say so. I recently had the same thing happen to me in my 02 SANTE. Was forced to buy 91 octane (10% ethanol). Let the gas sit for a couple of weeks and then when I took it out was hard to start and sounded rough. When I would try to give it throttle it stalled. My brother who happens to be a boat mechanic for volvo engines said it was probably the gas and said to put two cans of sea foam and let run for 20 minutes. Solved the problem and was running smoothly about a quarter of the tank in. Told me to never put gas in boat that contains alcohol. Says this is the number one cause of why boats end up in the shop now a days.