unpacking exhaust...

[blarp23]

i have heard that unpacking an exhaust can give you a few hp... but some say that you would have to re tune the bike... and one know about uppacking a exhaust and leaving it that way...?

[ben2go]

I haven't done it,but any time you open up or free up the exhaust, it's best to rejet to avoid lean running conditions.

[blarp23]

true

[Chuck]

AFAIK Stock exhausts don't have any packing.  They have resonating chambers and other science to do the silencing.  They're not meant to be modified, so there's no easy way to dis/re-assemble them.

As for aftermarket exhausts - well that varies.  You usually have to rejet for any exhaust change.

[jordanearl]

i traded my yoshi to a guy for his stock, plus cash, an when i got it he had drilled holes out of the back, it sounds identical to what my yoshi did.  the bike was rejetted for the yoshi, so i just left it alone an bike runs like a top

[blarp23]

as far as rejetting goes what all has to be done?