Guys, I Need Your Help.

[Scootin 81 C20]

Hey guys, I just went out to start my truck to move it to the garage. I started the truck and noticed that it is starting rougher everyday. Well it started and I heard it backfiring and running choppy. My parents were out in the back yard with the dogs and they told me to kill it because it had flames coming out of the exhaust when it backfired. Here's what I need your help on. What can I do to diagnose and fix this. I have noticed it running rougher for the last week and yesterday on the way home it was cackling louder than usual. So please guys, I really need your help as this is my daily driver.

P.S. If this post doesn't make sense, I'm really shook up right now at the fact that it may be something seriously wrong that I don't have the funds to fix.

Thanks
Benjamin.