I picked up a 79 ds125 last year to teach my daughters to ride. I went to upgrade to a newer bike this year and the best offer I got for the old ds was $25 :-( Sooo... Forks and shocks off of a 79 cr80 (added 2" travel) Removed the airbox with an inlet the size of a mouses hinney and put on a UNI pod 2 stage filter, WAY bigger main jet to match Rebuilt bottom end including tranny, removed all the stupid oil pump stuff and yes I premix now New wiseco top end bored up to 128cc, stock is 123cc not much but hey, every little bit counts UFO mx fenders Handle bars off of the cr80 because the old 60's 70's style make you feel like Rose on the bow of the Titanic. The only thing I couldn't get was a pipe so it's still stock. I thought about looking into a custom pipe but you gotta stop somewhere :-) It rides like a COMPLETELY different bike. Much more control, it doesn't bounce and hop like it used to. And in the tight stuff I can almost keep up with my sons cr250... Well ok, I'm lying about that. He can dust the 125 before the first turn and the CR isn't even anywhere near being on the pipe yet. But it's faster than the neighbors crf100!