Jerry B

Fountain with twin 502 EFI.
Did not see much run time the last two years due to family health issues. There was about 40 gallons of old fuel in the tank. had been treated with stabill. This fuel would have had at least 10% ethonol.
Anyway we put in 92 gallons before heading out for the first time this year. Ran fine for about 15 minuets.
It was turned off for awhile. Then when we took of again it would not run right. I have had vapor lock many times before but this was very different. Port engine sounded like it was running on 4 or 5 cylinders. First thought I had an engine problem then the other engine started to run poorly too. After listening to the engines it seemed to get a bit better. Still did not accelerate good at all. Did get it up to speed and thought it might have straightened out. Back to idle again and tried to take off again. both engines just dont have much pull. Put it on the trailer and took one of the fuel filter/water seperators off and empty it out. Didnt see anything unusual. I blew thru the line going from the filter back to the tank and was able to blow thru it. anyway I'm having a hard time thinking anything but fuel. Not knowing what I would do with 130 gallons of bad fuel, If that's what it is I deceided to take it to the Fountain dealer at LOTO, "Raymonds". Dont know how soon they will get to it.
Usually I would fix these things myself .Anyway just was looking for some input as to what might be going on.
Dont know if the ethonol is causing this problem but it will never get it again.

Knot 4 Me

Being that you had 2 year old ethanol gas and such a large percentage of the tank empty, it is likely you had quite a bit of water in the tank. You would have been better off draining the tank of the old fuel before topping off with fresh. Even though you put a lot of fresh fuel in, it probably cannot overcome the 40+ gallons of crap fuel and water.

Jerry B

I'm thinking along the same line. Wonder if the vapor seporator tanks have water in them. I did not take the top of to look . I have been reading all these horror stories about burned pistons. Hopefully there is no internal damage. It was not ran very long after finding we had a problem. Sometimes it doesnt take long so keeping my fingers crossed. The guy I talked to at the shop was not a tech but he didnt think I would have to throw away all the fuel. I still think it is a fuel issue weather it is the new we just put in or what was left over. To me condensation seems most likely the cause. We will hopefully find out in the next few days. What ever the problem I will buy ethonol free fuel as long as we can still get it.