riding the 50. bustin some wheelies. notice a loss in power, sounds normal so i open it up in first shift to secound. wide open throttle 50 just shuts off and rear tire seize's and i skid to a stop. throw it in neutral push it into the shade wait a minute and kick it over. starts fine i haven't let it run cause if i spun a bearing i don't wanna ruin the crank. what do i do?

02 XR50

 

sounds like it overheated mr shakey. piston gets hot, expands, temporary seize, cools down and your good to go. if you would have spun a bearing it'd be knocking noticably

 

yeah so i further inspected it and i think it has a oil leak some where on the bottom and it took 3/4's a quart of oil. so i filled and rode it for an hour. checked oil and seem'd fine. just gotta keep a closer eye. scared the **** outta me i didn't know if dirt bikes had that kind of protection with a "temp seize"

 

you gotta remeber the oil pump is in the front of the motor
and riding wheelies takes the pump out of the oil
if you have no oil to begin with you can see where this would cause a problem
luckily for you it has a roller bearing cam instead of a machined bearing cam or you wouldnt be riding it anymore
the only way to kill one of these motors is to run it with no oil