sounds like your mid is ok if your bogging starts when wot comes than I would move up to a 300 main and try it. to move the needles you need to take the carb tops off turn them upside down and pull the spring back, move the cable catch out of the groove, take out the two little screws the rest is self explained by looking at it apart.when taking apart the frist time is a pain but once you do it about 100 times you will get used to it. just be careful when putting it back together not to strip the carb tops.