Hi, I'm trying to figure out whats a good jet setting for my 21mm pwk carburetor on my motorized bicycle. My elevation is 164ft above sea level. I first had a 105 then moved up to a 125 and it lost speed at least by 3-5 mph. I have a cdhpower pk80 engine, 36 tooth sprocket, 21mm carb, and the mz65 pipe replica from cdhpower. Need help. Trying to do at least 50mph on this thing