Well, the day finally came, sea trial and delivery of new to us 2000 FV270. 5.7L EFI, not the MAG model. When picked up the boat had a little less than a 1/4 tank of old fuel with stabilizer in it. I topped up the tank with premium on the way to launch.
Engine fired right up, oil pressure all good, idled like a dream. Hit the throttle to get on plane, and a little sluggish at first, but first time on the water in over a year. Finally up on plane, and all of a sudden, engine cuts out for a second, two beeps and then comes back up to speed. Shut her down, checked oil levels, drive oil tank, etc. All good. Start her back up, no problem, throttle up, just past 3000 RPM, same thing, engine cuts, two beeps, then back to speed.
A call to the shop suggests that it's just the "old" fuel working its' way out of the system, but as we try and continue, issue crops up with more frequency, anywhere from 2500 RPM and up. At no wake speed, no problem, runs like a champ. IAC? MAP sensor? Simple as gummed up fuel filter?
"Knot Quite Shore"