Sounds like a trip into the primary is in store. Check out starter and compensator.

 

Metal on metal sound could be 2 things, the starter gear not meshing properly with the teeth on the clutch basket or your starter drive over run clutch is in the process of failing. I believe that 07 was the first year for the 96 ci engine and the factory did not upgrade the compensator from the 88 ci engines. The compensator frequently "bottoms out" (runs out of travel) and slams against the limit. This transfers a tremendous shock load back to the starter clutch and starts the accelerated wear process. The only long term fix is to replace the compensator (also requiring a new rotor) AND the starter drive which contains starter clutch. Many have has at least temporary luck with a less drastic approach. Some have replaced the battery, and with a good solid initial pulse of torque, the starter clutch locks tight and doesn't slip, eliminating the noise. Others have replaced the compensator and the noise went away. It is up to you to decide how many times you want to take things apart attempting partial fixes before you do the full job that needs to be done.