You slide the washer on the needle so it lifts it away from the carb. This will give you more fuel in the mid-range. Dont add more than two though. Turning the air/fuel screw clockwise gives more fuel too. Remember not turn more than 3/4 turn. If you feel that these two things didnt help try using a 42 pilot and 85 main jet. Leave one washer and fiddle with the air/fuel screw again. I suggest you ditch the airbox and get a pod filter and add the jets. Just my .02