I have 2004 r50, and have searched around the forum but can't seem to find what a brand new stock motor will compression test at. Anyone know?

 

Cooper: (167 - 247 psi)

Cooper S: (131 - 196 psi)

This is from Bentley, I know the numbers have a pretty good difference, but as long as you're within this range and similar on all cylinders (max difference of around 7 psi between cylinders), then you're fine.