most 125 dirtbikes make great power for its displacment problem it does it only between 10,000 -11,500 rpms not exactly ideal for a quad rider ,i have built 125 based blasters that made 35horse o na dyno on gas turning alot mroe mass in the rear than a light dirtbike tire and no big axle dual atv tires hubs bolts and rear assmebly etc ..,all that makes a huge difference o na dyno ,but like i said peak power isnt much to judge the speed or overal lperformance ,the modifed 125 blaster powerband is definitly for drags reving over 12,000 rpms and not suited ofr what most people would consider ideal i n a quad application ,i would say a stock piped only 125 dirtbike motor in a small atv frame would be lucky to hit 25hp if it wasnt highly modifed ,a modern 125 single offers pretty much no lowend torque,depneds how you like your power envelope ..on a track they can work great thats for sure,i know of a couple drag blasters that would i n a straight line drag crush about any modern 125.... or 250 dirtbike for that matter