Originally Posted by proneto911
i might just empty this tank and go up to the 32:1 to break it in then to 50:1
Before going to a 50:1 mix make sure the oil you plan to use is formulated for that ratio. Some are, some aren't. Read the label. Most quality 2 stroke oils will be safe at 32:1.
As for the "brass screw", it would help if we knew what carburetor you have. There are idle speed screws but they require a small spring under the head to keep them from vibrating out. A photo of the carburetor and the screw would help us offer more information.
Good luck, have fun and ride safe.