I have to pull the cowel too and re plumb it. I think my valve might be the problem too. On mine, it is the 91 FX, it idles fine, just when I go to full throttle it runs fine for about 20 to 30 seconds and then dies like you shut off the fuel. I got it to run longer, but there are so many bubbles in the line now. Has to be sucking air somewhere. I have to check all the lines.