The only exception is that (as Paul mentioned) some markets came with a "learner restricted" setup which included an additional hole in the slide that limited output; Australia for eg. Again, engine output is the same once the slide hole is blocked.
approximately 34hp at the rear wheel is what all year KLR engines produce when running properly. you can get another 2-4 with a KLX Jet kit, snorkle-ectomy/air box mods, decent filter and good silencer. 3-4 hp boost is available from the 685 BB kit. Beyond that you are looking at cams, porting.....or maybe one of Eaglemike's 719 kits......but even all that won't likely get you much past 45-50hp.
The KLR "is what it is". The desire for big HP (i.e. 50-60) is an itch best scratched by another bike......the KTM690R comes to mind.
Last edited by DPelletier; 08-07-2018 at 10:04 AM.