Impossible to answer, depends on what model KTM you have.
NGK Spark Plug BR8ECM
br9es, br9eg, br9egv, br9ev, rn2c, if it fould all the time something else is wrong
I have a 07 KTM 525 XCW and the manual call for 6mm on plug gap.
br10ecmix
0.60mm
NGK BR8ECM
We use the nkg br9eix
NGK BR8HS with a .032" (0.8mm) gap
0.7 mm
under the gas tank
In the center of the head (on top of the cylinder).