Hi Friends, I have been meaning to register for a while now but kept viewing as a guest as I guess a lot do, I have got a China Girl "80cc" engine kit on a Carrera hard tail mtb. I use the bike on/off throughout the year to commute to work. I have done a few little upgrades over this period of time - fit fuel tank to a seat post rear rack covered in a hi viz cover. Removed the chain idler & cover. Fit NGK spark plug. Fit better hardware to engine head/mounts. Fit "mini generator" from Wonderful Creations, been a great help espeacially in winter!! Fit MR16 5W head lights x2 , and rear brake/tail light, front/rear indicators, all powered by a 12v SLA battery. Everything else is pretty much standard. Not sure what next upgrade would benefit the bike? I am now getting ready for a second build with something a little more punchy like a Morini! I am not sure if a donor frame will be ok if so what frame would be ok for say a 6hp morini engine? Bye for now, Pete.