Here I go again guys,

I'm selling 1 of my boats 1995 389 F/S with a Johnson 150. I get to the lake with the potential buyer and right as we get to WOT the motor starts to hesitate and surge. It does'nt do this until your plained out. It idles fine and starts great, Could this be a fuel filter needing replaced or what? Have not had a lick of trouble out of this boat until it's time to take the buyer out on a test run. It has set for a while and not sure on where to start looking.

Thanks for your knowledge and advice in advance

Mudcat27