Hi ... My quest is to get a registerable, light, reliable, dirtbike that I can flat foot (28' inseam) I am almost complete with my Honda grom with cbr300r engine and want a dirtbike with the above checklist. Has anyone done a build like this? I know it would need engineers cert... but after doing the grom eng cert its pretty straight forward. I am pretty sure the z50 engines are a straight swap into a thumpstar. Would a kitaco 124se bore up kit be more reliable than a chinese engine? any help/ experience / advice with this before an outlay $$$ would be much appreciated.