2005 4 stroke sputters in mid-range

I have a 2005 Yamaha 115 four stroke that sputters in the mid range band of 2600 - 3000 rpm. Idles fine, wot fine all other ranges fine. Oil is good, filters are all new, plugs have been changed, even squeezing the fuel bulb doesn't affect this condition. No water in fuel. The engine has been babied and only has 390 hours on it. This is driving me nuts.

[boats.net]

It would need to be run on the computer diagnostics to see if anything is out of normal range or irregular readings From sensors.