http://www.gasgasrider.org/forum/forumdisplay.php?f=52
If you have not found this yet. Read some of the posts in the
Mini Gassers forums.
Since these SuperMoto model EC50SM are rare in the US I did not
find much useful information and no real source for engine parts and
upgrades.
Although Treatland.tv and 1977scooters might lead to USA resources.
My Derbi50SM and my friends GG EC50SM in Las Vegas.