About 1 year ago i purchased a big bore kit from High Lifter and installed it in a 2003 rancher with much sucess . I used this quad at work to pull a brush assy. that weighs about 400 lbs. alone , but mostly i used it to run around the field (football) also played in the mud when i was home . The kit came with .J&E piston ,Cometic gaskets,and a new cyl. sleeve (cant remember the brand) cost was around 350.00 for the kit plus 100.00 for machining . Probably about 75% more power than stock , had to modify the crankcase vent though it was sucking the oil out of the motor through the air box!! I have installed big bore kits before but this was the best response i have ever got with out changing cams or jetting Enough tourqe to pull front wheels up in third gear from a rolling start. Sadly after about 9 months of hard work the head went south and flooded the motor with gas , I sold it and bought a 05 750i brute :rockn: maybe the guys at work wont kill it !