I just bought a used 2003 Z400 It has a Yosh RC 3 Pipe and no spark Arester so its pretty loud , so I bought one and put it in , do you think I need to rejet, its just being used for trail riding

 

I don't think you will need to re-jet..... ..... but I could be wrong....

 

It will richen it up a little but it really just depends on how he had it set-up. I would suggest doing a plug check anytime buying a used quad with mods. You never know how they jetted or if they even bothered to. Just give you a good idea where it stands now that its yours. [img]i/expressions/face-icon-small-happy.gif[/img]

 

you might. I would check it just to be sure