Mauricez4, don`t worry man, you are almost done. The mixture control screw is on the carburator right side ( muffler side ). Look your carb from that side and you`ll see a hole in the center, next to where you attach the throttle linkage. Inside that hole you`ll see a small screw head, thats the mixture control and is only for adjusting the idle speeds mixture. Run your engine and warm it up at half throttle, then shut it off and adjust/close that tiny screw 1/16 of a turn clockwise, start the engine again and you`ll start seeing the difference in acceleration. You will repeat that 1/16 tweak various times until your .46 accelerates smoothly.
The high speed needle is the big/long one, and you adjust that one at full throttle. Run the engine at full throttle, start opening the needle ( counterclockwise )slowly until the engine starts loosing RPM`s, you are richening the high speed mixture then, then start closing it until the engine reaches max RPM`s, then open the needle again a little bit so you loose a bit of RPM and leave it there. You are set.
You will have to repeat this adjustments later as your engine gets broken in further, just repeat the above. If you have any questions feel free to contact me anytime.