Originally Posted by
Zeeb
For lack of a better explanation; there is no "G1" version. It's just the original as it's just a "G". Changes/improvements started coming with the "G2" version.
G marked the introduction of valves under the cover and was a pretty big step up with red parts over brown cans and better acceleration times. Before that they had the gold parts and external everything. They even had a gas start and kero start version, but I don't remember the codes, might have been F (fuel start).
Starting from the G2 version I believe, KT moved away from the older xicoy ECU and into their own version of it with color GSU.