I just bought a exhaust the Polaris Pure Exahust for my 04 Predator 500 do i need to rejet?

 

Try it first and see how it runs and whether it has any hesitation or bogs. Most important thing is to check the color of the plug after a high speed run. Electrode should be tan to a medium tan color. If it hesitates or plug is whitish,then rejetting is needed. Some run ok with stock jets,other just need a slide needle position change,others may need to bump up the main jet and needle position.