Gator was correct in saying that you need to be sure the muffler connection is air tight. The slip on is slotted on the end and these slots need to be sealed. I used RTV and it solved the leak. Shine a bright flash light around the muffler connection and you will be able to see any light from an opening by looking into the outlet of the exhaust. I was surprised to see the light and the RTV was the answer.
If set screw removed, and unable to turn baffle in muffler, you will need to remove muffler from bike and use broom handle etc. and using a sand hammer push baffle out from front of muffler. Don't ask me how I know.... A helper may be needed.
Already tried that with a metal bar didnt work..Im to the point of using a winch or ratchet strap or hooking a chain up to the baffle and put the chain in a vise and pulling and yanking I dont know im at a loss
If you have a butane or map gas torch heat up outside area where baffle comtacts outer tube . don;t turn chrome yellow just expand the outer tube .. this also works on stuck muffler to head pipe joint.. ox acsedoline touch is to much . this has worked for me..
I would suggest to Ask the manufacturer and see IF they suggest a way that will work.. They must have More than yours Tight..
I have used the method with the stick and it always seemed to work.. Make sure ALL the keepers-fasteners are out.. If there is a pop rivet on the end besides what you removed, It also probably holds the baffle..
Just a little update I am sending the one muffler back to Rush the baffle is stuck in it. I ordered 1.75 baffles. I was taking or trying to take the baffles out to get ready and the one came out pretty easily the other one though the little bar in the back that you use to twist and pull it out broke off when i was using a wood piece to try to hit it out. With out that your pretty much (Edit). I only got it to come out about 2 in. I called rush and they said they would replace the shell no questions asked. I just thought about it I hope they send another baffle with it a 2.25 in so I can at least have the set if I want to put them in or sell them on ebay...lol...anyhow good customer support there I was happy they were replaceing it.
Well I got the muffler back put the smaller baffles in hi temp rtv the muffler to the head pipe and the backfire is gone. I dont know if it was one or the other or the combo of both but its gone thats all that matters.