You are probably right. I was doing a search on the forums to see what everybody else was doing to cure this problem. And one of the posts suggested kicking the idle up. Something about a decompression valve kicking in. I was kind of thinking it might have something to do with the jetting. but wasnt sure. I was told their should be no jetting change necessary when installing just a slip-on and not the headpipe. I think ill try a plug chop and see how its running. Thanks for your input!

 

Decompression systems work with the exhaust valve, so it would not cause a backfire thru the intake side...

Good luck