hey guys, yesterday while riding i noticed a very loud backfire. i kept riding for a few more minutes, and the bike died on me. i tried to start it but as soon as i cranked it. it backfired again. i let the bike sit for a few minutes and tried to start it again. it started up perfectly, so i rode it home. my friend rode it for about 10 minutes and brought it back and said the bike didnt do anything to him, so we all went riding. the bike ran fine all night until we rode on the highway and it backfired again, and a flame shot out the exhaust. the bike bucked on me a few times. then it ran fine on the way home. what do u think is causing this backfire???? your comments are greatly appreciated

 

your ignition system