I have a 02 700 and had it but mine was worse, it was bogging at 1/4 throttle. did the same as you did and sprayed it with carb cleaner and nothing. The way I found it was after cleaning the carb the second time, when I was puting the carb back in I found the crack. I fixed mine with sylicone on the out side and I put ca glue(its used for radio controled cars, gluing the tire to the rim) on the inside. Worked very well, my problem now is that my rings are bad from sucking dust, so get it fixed soon. Just parts to do it are between $240-$300.