have you ever seen this

[ageerx]

i took off the left side engine cover to check my whatcha ma doodle. i don't know the technical term for the metal bowl thing that bolts to the crank and has four magnets attached to it. bear with me, i am new to the 2 stroke mechanics of motorcyles. anyway i pulled it off and one of the four magnets had separated from the housing and another on had broke in half. i came to the conclusion that this is why my bike is backfiring when i try to kickstart it and it is also why my bike won't idle. has this ever happened to anyone else or am i the only unlucky rmx 250 owner in the world.

 

[merlinnn]

Happened to me on a YZ 250, not sure why as the nut was tight and no freeplay in the crank bearings. You will have to replace the flywheel and check the crank seal etc to make sure there has been no damage from the magnet debri. I think the back firing is a result of altered timing due to the missing magnet.