Re: 57fastwin,lowspeed jet problem.
Ditto what chinewalker said. The needle threads through the "spinning barrel". You should remove the barrel to clean the passage thoroughly, then reinstall it, followed by the packing material, then the plastic packing water, and finally the brass nut the needle passes through. As you tighten down the brass nut it will compress the packing washer, which will in turn compress the packing, which will in turn compress the barrel and prevent it from spinning. Start by tightening the brass nut down about 1/2-3/4 of the way. The needles should still be able to spin, but should also have a bit of friction on it such that it can be adjusted ans stay in place. Once you've got the idle dialed using the lo speed needle tighten down the brass nut the rest of the way. This should prevent the needle from moving while underway. This link wil help you set the carb once cleaned too.
http://forums.iboats.com/showthread.php?t=167352
