I HAD A 86 YZ 80 BEFORE MY 250 YZ, ALSO HAD A 350 WARRIOR. i wanted a 125 cause i thought the 250 would be too much. when i first rode it i was sooooo scared, like turning a mack truck when i was used to a UGO. but not long after i was glad i had the 250. i ride a lot of hills and in silt and it really bogs the motor so a 125 wont cut it for me, plus i am 175-185 lbs now. 125's are cool i just like the fact that you can be in third barely noving about to stall at the bottom of a hill, tap the clutch, floor it, instant powerband, and up the hill that everyone wants to do and i'm DOING it!
When in doubt, GAS IT