Indeed, live bomb in the room! The correct answer is "the one I own".
The USA market opening model in '03 has 'introductory hp' and like many first year bikes is the quickest. However it has the smallest brake rotors of any Gen, no ABS, flaccid suspension and the highest risk of having premature valve guide wear due to excessively tight valve stem seals.
The '04/'05s are probably the most trouble free years. With ABS either of these two years is probably the best compromise of all years and Gens. Good reliability, good performance and a good ride with no real warts.
The Gen IIs got a bit heavier and geared a bit taller which ever so slightly cuts into performance. The chassis was altered with a longer rear swing arm giving an improved ride at a tiny cost of cornering. The Gen IIs got a better dash with the exception of the turn signal indicators and the Gen IIs come with more features and built-in adjustability.
The '06/'07 are the most troubled of the Gen IIs with some strange ECU and throttle changes. All of the Gen IIs have had a number of significant recalls. The '08-'10 are probably the best sorted out Gen IIs. The elephant in the room is the grounding spiders. There are multiple ground points that have been proven to fail in a significant number of FJRs. The Forum at your service here -- we can help diagnose a ground failure, supply you with 2-3 solutions that will prevent failure and help fix failed wire harnesses. The question is if Yamaha will help the Gen II owners.
A strictly clinical listing of all the years and the changes can be found in the
model year comparison matrix.
Edited to ask: So, I see you are built on a truck chassis, are you indeed a caber tosser? You gots the build!
