Q. Which is best Gixxer SF, R15 S and KTM 125 consider price as well. - YZF R15S?

Usually this engine gets heated bit., But not like for two min.. I have risen for Pondicherry & back in single day, so it was tired, and got better next day itself. You better show you Honda to showroom and ask & try to replace before any major problem.

R15S wins hands down.

R15s is the best option in this category.