If you're running the original fuel lines that came with the ski then I'm going to bet those are your problem. The FX was built before they introduced ethanol into the fuel. The ethanol will eat those lines up like mad leaving your fuel black or discolorred. Seadoo used the old gray Tempo lines and would deteriorate in a way that would fill the in carb filters with a type of fiberous material. Make sure your fuel is ethanol free, it doesn't matter if the octane is 91+, most stations now still add up to 15% ethanol. I had to research the stations local to me for weeks only to find that Shell 91 was the only totally free from ethanol higher octane fuel. Most stations didn't even post it on the pumps that their above 89 was still 10% blended ethanol. Petro Canada boasts an "ultra 94" with no indication of ethanol but it's clearly detailed on their website it's an ethanol blend, I think it was a higher concentration too if memory serves.
