[bikeaholic]

generally speaking no -

an exhaust pipe change on v-twins usually does not require re-jetting the carburator
depending on the pipes some minor adjustment to the air/fuel screw may be needed
on some bikes

fuel injected bikes will compensate automatically without problems in most cases

however if you modify or change the intake system by using a high flow filter element
or opening up the airbox re-jetting will be needed on carbed bikes to add more fuel to
compensate for the increased air flow and correct the lean running condition that will result
jet kits are available for nearly every bike and are not expensive-there are some very small parts involved though in the kit and if you are not good at working with small parts
have it done by a qualified service tech.

fuel injected bikes will require remapping of the bikes computor to add more fuel to
compensate for leaness.there are several units on the market that can be installed
on f/i bikes that will take of this,but the best way is to have the bike put on a dyno
and the air/fuel ratio adjusted through out the entire rpm band and doing each cyclinder
independently for maximum effect-this requires the use of a laptop and tuner who is
familiar with these type of programs-once completed no more adjustment will be required

remember when changing pipes to use new crush gaskets for a proper seal at the exhaust flange-do not try to re-use the old ones,they will most likely not seal properly
causing an exhaust leak