Motorcycle Repair: pw 80, middle groove, float bowl

Question
My pw 80 kick starts ok with the choke down then when its wormed up i try to put the choke up and it revs high on its own. And when i try to ride it cuts out and miss fires and has less power then useual.  Yours sincerily ryan bennett

Answer
Ryan, It sounds like the carb needs to be gone through and cleaned and readjusted. Pull the carb and bowl check the float bowl and chamber for cleanliness and float height. The mix screw should be out from seated about 1 1/2 turns to start with. Also the slide in the top can get turned 180 degrees and run fast but not much control. The needle that hangs thru the slide is adjustable. Remove it and make sure the clip is in the middle groove on the needle. There are usually 5 grooves also make sure the air cleaner is good and sealed as these wont run good without one. When you install the carb make sure there is a good seal between the carb and intake manifold.