I have a 2014 that I bought used that came with the Mo-tech frame sliders. I foolishly decided that I could slide some large nuts behind the slider, that would act as spacers and kick the sliders out some and they could then double as highway pegs.....(I know I'm a moron)........ anyway, it was working but I had unfortunate driveway tip overs on both sides. Since the slider bolts were essentially shimmed out, they bent during the tip overs probably due to increased leverage coupled with them not fully threaded due to my "nut spacers"........I cannot tighten them up so I took them off. I have since been told those bolts MUST be installed as they are part of the engine mounts. I don't even know if the bent bolts are stock, or if they were part of the Mo-tech system. I have been on various sites trying to identify the bolts I need, but they all seem to use the same exploded parts diagram software that I've never been able to read properly.
These stores can usually match your hardware (size & thread) and should have various lengths on hand. Once you know what you need, call around for availability.
Order the bolts from a dealer or Amazon, by Part Number.
2008 FJR1300A - Pirelli Angel GT (Spec A) tires, RDL seat, TPMS, GPS digital speedometer (Amazon ~US$28.00).
P.S. Life is too short, and health is too valuable, to ride on cheap parade-duty tires.