why wont my 250r start

[atcrider1]

i just redid the top end on my 82 250r 2 days ago, after i put it together i broke it in and it ran awesome, now it wont start and just backfires loudly out of the exhaust.


what will make it do that?


thanks alot
cody

[jeffatc250r]

A junk plug? a sheered flywheel key will make that happen also.

[Thorpe]

X2 on the plug...