NGK CR8EK or NGK CR8EiX (Iridium)
Impossible to answer, depends on what model KTM you have.
NGK Spark Plug BR8ECM
the stater needs to be rewound
First disconnect your kill switch, if that is not it, check your plug cap, then if that is not it go on to your stator.
0.7 mm
NGK CR9EKB 05 NGK CR9EKB 05
bad plug bad plug cap stator
I have a 07 KTM 525 XCW and the manual call for 6mm on plug gap.
br10ecmix
0.60mm
NGK BR8ECM
You didn't specify what size but most dirt bikes will run a gap of 0.5-0.6 mm.