I was running my Sportwerks 21 and it crapped out. When I went to start it back up it wouldnt stay running and when I did get it running it sounded different and when I gave it throttle it sounded like it was back firing. Whenever I try to give it WOT it just shuts off. I took it apart and only saw minor fragments but nothing that would bind the engine. Please tell me if I clean it out it will work like it use to.

doesn't sound good, "minor" fragments are too big. what exactly got into the engine and how?

The air filter came off and Im not sure how long it was off.

that's bad no matter how long the air filter was off

Take the motor apart and give it a thorough cleaning and add some after-run oil after you put it back together. Make sure to use some good sealant to prevent air leaks while putting it back together.

I took it apart cleaned it used the after run oil and still same problem. I may try to put up a vid so you can see what its doing. It just seems like its starved for fuel when I give it throttle.