i was out rideing today and my 650 wanted to start backfireing so i shut it down and when it cooled off it ran fine till it heated up then it started doing the same thing if anyone could help please let me know thanks for the help by the way it my first day to the site

 

jetting? bad gas? coujld be a few things...i had a problem liek this nad it was bad gas

 

does your fan ever come on?

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comes on when the motor gets hot i was thinking something like bad gas but wasnt sure cause just the day before yesterday it ran fine

 

how many turns out is your air/fuel mix screw?

 

air leak at the header will cause backfireing too. check bolts