Hi ,you are not alone i have one to ,a brand new,i like it a lot,,it made 55 from the start,then i replaced the variator boss,and put in a jet size 86,i think 84-86 is right fore the orginal carburator and cylinder,,and to day i cut the violet cable in the cdi cable wiering,i cut the loop..now it makes 60-65 on a strait road,,but its not very qiuck,but it runs nice and quiet,,my city has only gone about 90km
and il think when it is broken in after 100km it will go better,,il have to adjust the valves exactly then il think it will be a bit quicker.
im 38years old,live in stockholm sweden.by the way a tested the spedometer with a gps and when its shows 55 it is only 50 in real speed,