First, Big Blue: Pretty much all stock '04 YZ450F. You can see me riding it here (with a sore left elbow that I'm babying): http://www.youtube.com/watch?v=YxINfjqOruU I like it pretty well, but I miss changing pistons, jetting, mixing oil/gas, cleaning silencers, swapping clutches, and...what'd I miss? So I picked up a lil' green machine last week: '05 KX125. FMF pipe, revalved suspension, otherwise stock. I was breaking in a new piston/rings by doing short loads, shifting 1st-3rd. "Pretty fast!", I thought, "Almost as fast as the 450F!" So, I got the 450F out, warmed it up and did the same runs. First run, the low end hit and just about lost me off the back of the bike. 2nd run, I carried the front wheel about 18" off the ground the whole way.... No, the 125's not NEARLY as fast as the 450F! It's still fun, though. Glad I got it.