I think that Akunar in Thailand sells a complete Honda CBR125R bore-up kit, they have the standard to 150cc with 4-valves DOHC... but you not have to stop there, you can go as high as 198cc (or even bigger maybe).
I'm not sure if Akura also ships outside Thailand, but I believe so, you can contact them or visit their website by looking in our web directory under Motorcycle Parts.
I would like to know if there are any distributors in Canada or the United States that stock the Honda 125cc to 150cc conversion kit. Honda Canada doesn't stock it and won't consider ordering it, and I can't find anything on line. Is there anyway I can order one? I have a 2008 CBR125R with fuel injection and I would like a little more power.
Thanks very much, Gary