Ok guys i just got done reading on Falicon's website and they mention that they can stroke your crank!!! I have not talked to them yet to see if its possible on the xr650r but i dont see why not Now all i need to find out is how many mm's i can go without running into valve clearance problems. If anyone knows about how many mm's you have till the valve hits the factory piston please let me know. Also by increasing the stroke, i believe you will ultimately increase the compression because the piston will be traveling closer to the cylinder head so does anyone have any ideas how to calculate the compression ratio when doing something like this?? I am hoping to be able to go at least 2mm and still have enough clearance for the valves, if not i would like to go 4mm and have a custom piston made. I am going to call Falicon tomorrow and talk to them and see what my options are. I will let you guys know what they say. Falicon makes custom length rods so as of right now the plan is to get a 4mm longer rod and having a spacer plate m ade for under the cylinder which should bring my cubic centimeters to over 700!