I'll be joining the CRF450X ranks in the next couple weeks...sort of. I'll have the bike, but I won't be riding it. The bike I'm buying is a steet titled & fully legal 2005, with a locked up transmission (classic 3rd/5th seizure most likely). All stock mechanically, other than the Baja Designs dual sport kit. Anyway, I'll obviously be tearing the motor fully apart for inspection and repair, and doing what I can to prep it for a (hopefully) much longer life in dual sport service. For the next couple months my wrenching time will be very limited, so I don't really plan to have it running until maybe later in June. In the mean time I'll continue riding my 'lowly' KLX250S, which is staying in the stable for the time being. The CRF doesn't have terribly high hours/miles...although the exact numbers are unknown. Best guess is under 100 hours of fairly easy use. Inspection will dictate whether I replace the piston or valves at this time...but when I do, I'm planning for a TRX-type piston and stainless valves. It will need a big tank, as I'd like around 150 miles range in dual sport mode...so I'm curious about others experiences with the Acerbis 4.1 and the IMS 4.0. Comments on fit, durability, level of radiator protection (or lack thereof), etc? I'm used to riding with this type of tank on my KLX, so the extra width really doesn't concern me.