A.O.A Friendsmeri bike ka head light bulb har 3 4 din bad fuse ho jata hy. i dont know why. kal start karny k bad jis trha he head light on ki. on hotay he off ho gai. Low point theak chal raha hy ab. woh b 2 3 dino bad ur jaye gaVoltage ka masla hy ya kuch orBulb 20 wala b use kia (China) hy or 85 wala stenlay ka b
I think holder is loose and loose holder makes spark resulting in damage to bulb
which is your case
just check your bulb holder properly
i think it's your bike's rectifier problem, visit any good bike electrician.