Yes. The mufflers I currently have can't be disassembled. I had inserted SS pot scrubbers into the body of the mufflers via the inlet. They eventually got packed too tight and were causing too much restriction, though the noise was greatly reduced. I removed the scrubbers and then inserted 2 of them into the baffles from the exit. Still louder than I want, but flowing better. No problem hitting red line in 4th gear.
I'm thinking that there must be some weird resonance going on, as I'm currently jetted rather lean, I had to lower the needles 1 notch below stock. I may try going back to the stock needle height and lowering the float level as I think it is slightly lean right now. Just ran out of time today. Don't want to be ripping around late at night and pissing people off when they are trying to sleep.
After about 5 kilometers today the engine just made a loud bang and stuck so I made a long black strip on the road with my rear tyre and I nearly fell down. It was sudden, no vibrations, no loss of power, no overheating, smoking... Just nothing suspicious 
So far I couldn´t dissasemble the engine because it is stuck and I cannot reach one bolt on the cam chain sprocket. Only thing I know is that cam, valves and pistons are alright. Luckily I´ve already found the tutorial by Volcom how to dissasemble it from the bottom. Gonna try it tomorrow. Wish me luck!
