Differences arent too many, the earlier ones had a 10 mm wrist pin, later had 12mm, I am not sure what year the change was, about 2003 I think. Some have a kill switch, some dont, some have a dimmer switch, some dont. My speedo goes to 80 kmh, some go to 100, wish I had that one. I dont know about the lag but if you derestrict your cdi you will have more revs available at takd off, however, I would recommend derestricting the variator first. If you are so inclined, you can have a lot of fun modding these little scoots. And hey, welcome to the forum, a great place to be.