When adjusting your end points for your carb, you need to look into the opening where the air filter goes and move your throttle open and closed. If you see the carb moving when you apply brakes from neutral you need to adjust it so that when full brakes are applied the there is no movement in the carb. Also same for throttle, you want to adjust the carb so the when you pull the trigger it opens just to the end of the hole wide open and not past it.
Your two speed will not shift if the motor is cold like stated above. You need to generate RPM for this to occur.