Headlight bulb keeps burning

Occasionally bulbs will fail for no reason. Replace the bulb and try again. If it fails again, then you likely have a problem.

Either lose bulb but most likely a charging problem. Get DMM Nd test voltage at battery while the bike is running. Anymore than 14.3 volts you probably have a faulty voltage regulator.

sounds to me like your voltage regulator is bad with out t working proper it will not regulate the voltge more gas more volts and kaa pow you will blow out your bulbs

Sounds as if the switch is worn or faulty , find a new or second hand switch to change it over with .

If your headlight keeps burning out, you probably have one of two conditions going on. First, your voltage regulator may be putting out too high voltage. This makes your headlight extra bright, but it also burns out the bulb much faster. You can easily check this by measuring the voltage across your battery terminals while the bike is running. You should get a reading of 14-14.5 volts. If you're seeing a reading above 14.5 volts, you've got a problem.
Second, the headlight bucket is supposed to insulate the bulb from some of the road bounces that can damage the filament prematurely. You might want to check that your headlight is mounted firmly to your forks and isn't bouncing up and down freely. If you can move it with your hands, it's too loose.
As a final thought, if you are using halogen bulbs, are you wiping them with rubbing alcohol before you install them? Fingerprints on the bulb will cause uneven heating of the bulb glass, greatly increasing the odds of cracking and premature failure.
I hope that one of these suggestions hits the spot.

voltage regulator faulty ,its built into the alternator

well, its not the "circut breaker" aka the fusebox, so there has to be a problem with the regulator. when you say headlight "blows" do you mean the actual bulb burns out, the fuse burns out, or the light just turns off? it matters. on a side note, if your headlight stops working, its normal for all the other lights to get a little brighter due to the extra power for the headlight going to the others.