Here's a service manual for a 2001 - 2003 F4I, It's a PDF so you will need to have Adobe Reader.

http://www.stephygee.com/f4imanual.zip

 

your tank will read reserve until it's running and held vertical (off kickstand) for a few seconds

if it's not starting you're missing one of 3 things compression (not likely), spark, or air/fuel

as asked earlier is your fuel pump priming when you turn the key or hit the kill switch to the on position?

to change your plugs you'll have to pull your tank, and air box off
the #1 plug is going to be the hardest to get out bc of the proximity to the frame
please torque them when you install the new ones, there's not much worse than stripping out your plug threads

another website for the manual is www.manualz.info