Outboard Problem

[Hackberry Hustler]

I have a 2001 Yamaha 4 Stroke 40hp. I have had absolutly no trouble out of this motor until now. The problem is that it will start and run fine until put under a load in the water. When I put it in gear and try to throttle up it wants to cut out and try to die. I have since taken it to my mechanic (who has been working on outboards of thirty years) and he has run every test under the sun, and finally we have come to the conclusion that one of the caburators is not working properly. He cleaned it and the problem got better but still not enough power to plane the boat. He then contacted Yamaha and there answer was to replace the carb cuz that model there are ports in it that just cant be reached to clean, and that they had so much trouble with that design that they later discontinued it and went to fuel injection. My question is has anyone else had this problem and what did you do. I personally have never heard of carbs that cant be cleaned and rebuilt at least once.