Where exactly is it blowing from? Strange for it to start after putting on new headers
Not sure I understand what you mean when you say its blowing "from inside the end" - do you mean it sounds like the internals are busted? If so I'd be tempted to suggest its just because of the different tone that the new pipes are causing
Mine was definitely more growly when I put on ss headers
it aint the tone, i can feel the end can blowing.
In the picture, were the exhauast enters the end can, there is 3-5mm gap. Its from here that it is blowing, that is what mean "from inside the end" can.
It is supposed to blow...
I have just shortened one of these cans and noticed there is a 3mm hole drilled into the base of the baffle...
I welded it up!
I can only assume yamaha drill it to allow water to escape..
If you look on the underside of the can you will notice another drilled hole just in front of the welded cap.
I chopped 170mm off the can, removing 2 of the resonating chambers and tig welded it back up, sounds great and has lengthened the power band without losing the midrange as there is still just enough back pressure..
So don't worry about the blowing, it has always been there!!!
You have just noticed it that's all