i had my bike('00 yz426) at my friends house today cleaning up some the plastics and making a whip mount for it. i rode it around a little. i rode it for maybe 30 minutes then set it in the garage for maybe 20-30 minutes. then i went to ride it again and after riding around the block a few times i found that the front brakes were wanting to lock up. so i took it back to his house and i could barely push it. if i pulled it backwards the front tire would just stay locked up. so i looked over the brakes a little and after finding nothing wrong with anything(that my friends or i could find) we just let it sit. after a while, like after it cooled a little(5-10min) it would roll again. so i rode it up the street and by the time i was on my way back the brake was already dragging. this was without using the front brake at all. so, here i sit wondering what it could be. i was at the honda dealer picking up a friends tire so i asked one of the guys what it could be. he said it could either be; 1. water in the lines 2. master cylinder is clogged 3. master cylinder needs to be rebuilt 4. caliper needs to be rebuilt or 5. return spring on the caliper was worn. so i go back and check the master cylinder seemed to be ok(not clogged). then i pulled the caliper off and there was no return spring so i dont know what else it could be. any help would be greatly appreciated. thank you and sorry for the long post.