The motor is a 1984 cr 500r (air cooled). I like the way the power comes in (very banshee like) just a different sound. Let me tell you its a pure rocket. The bike just pulls for days and jetting isn't even 100 %. It has a 175 main and tha DGL needle is on the very top notch. I plan to drop to a 172 and try the needle clip in the middle. As for as mods head milled for race gas, exhaust port widen alil, polished on intake side, .50 wiseco piston, cpi out frame pipe, stock carb board, and uni filter. I plan to go up on the exhaust port and transfer ports in the future. I'm no where close to being finished so if anyone has any questions just ask. Now LET ME SAY ON THING lol. The vibrations is not that bad as people say it is. When the bike is at idle is the worse. Who cares just take your feet off the foot pegs. You can not feel it in the handle bars at all ( I'm runing the bars off the 84 cr). When ever you are riding the bike slow or fast You don't even feel the vibration in the foot pegs at all. I will keep them videos coming with a helmet of course. I got a few boys a round my way with a Modded Banshee, Yfz 450, 400ex, trx 450r, 660r raptor and 700r raptor. I'll make sure i get the drags on youtube.