Ive got a 150 Johnson that has been serviced fairly regularly for years. Two years ago all the plugs were replaced and everything was serviced (Fuel lines replaced..tank cleaned)...but it still hiccups when running wide open. I am really at the end of my rope here..Ive had three mechanics look at it..and I walk out with a large bill. They claimed the fuel lines were dirty and the tank, but now they are OK (after mucho $$). Ive been using Stabil (duh) but it still hasn't helped. The "hiccup" still happens every once in a while, and my heart stops everytime. It has to be something in the engine, but I can't afford "speculation". The motor is old, but well-maintained. She has been a real trooper. I wanted to just throw this out there to see if anyone had any suggestions or a possible "diagnosis." I need her to last me just a few more years..but I feel as if she going to twist up on me during one of those coughs at high rpms. Maybe me and Dad will be fishin out of the jon boat soon (dammit he's half blind!). Any help/suggestions would be greatly appreciated guys...Thanks