There is a link for a PDF of the Honda XR650R service manual. I would search for that within the forums (search function on maroon commands bar up top) or on the www.XR650R.us website. Within there, you will find the timing procedure. I have the manual at home that I E-bayed for $20. FYI - I never disengaged the Timing Gear from the cam chain while performing my cam swaps. I unbolted it from the cam then used a wire to pull it upwards to keep the teeth engaged with the chain.