what to look for when modifying exhaust+stage 1 jets+ k@n....

[05 gs500f]

 hi all. im new to this board and the gs500. so i bought my 2005gs500f, replaced the air filter with a k@n am looking for an exhaust now and im being told to get a jet kit. is this truly necessary? or will my bike run just fine with an aftermarket exhaust and k@n? also, which stage kit would be appropriate for my basic add ons? lastly is this something one can do himself( sort of a novice, with some basic wrenching skills) or should i have a professional do it....

any answers will help...thx

[craigs449]

you will need to rejet the bike after these mods.  You need more fuel to compensate with the higher flow of air into the combustion chamber as well as the increased exhaust flow.  Hit The Buddha up for the proper jets for your bike, Jetting is DIY for anyone that is mechanically inclined, many tutorials on here and also the Wiki. Good luck

[05 gs500f]

thx craigs449....will i lose a significant amount of mpg with the jets (being that it flows more fuel now)? or is it minimal?

[jestercinti]

You will lose MPG since changing jets changes the aperture.  I went from 60MPG stock to 50-55MPG lunchbox and 20/65/142.5. 

Riding style, tire air pressure, and recent tune-up will also affect MPG.  I tended to ride my modified bike harder than stock.

The overall answer is it depends, but generally speaking, it will be lower.