Dude you have to stop multiple posting threads, Its getting annoying. You seriously need to make one thread about your problem and one thread only. Making multiple threads for the same question is not cool....
Anyway, A Yamaha Blaster does not have a battery, therefore there is no consistent source of electricity produced by the stator. This leads to an inconsistent glow of the headlight. When you rev it up, the headlight gets brighter because the engine is producing more electricity from the stator.