I put my white bros. R4 exhaust on my kfx 400! It came with a powerfilter. And it also came with a 165 main jet, which I didn't mess with. I'm at roughly 4500ft. It seems to me that a dyno would be the only way to really determine what jet to use. Is this true? Are there any basic guidelines based on elevation? Or should I just leave it alone?
On a side note, the exhaust looks, and sounds awesome! I haven't takin it for a ride yet though.

 

If I were you I would jet it .......Also sell The Z they are overated..[img]i/expressions/face-icon-small-smile.gif[/img] jokin..

 

Well I would, but I don't know where to begin. Are they jetted for sea level from the factory?

 

I just realized you were talking about the Z28. You're right they are overrated. But this particular one is just plain SICK!! And getting badder all the time. I actually was thinking about selling it. But only to buy another Z.

ZO6 that is[img]i/expressions/face-icon-small-happy.gif[/img]

 

Not sure on the 400..usually they are set for sea level...I would put the reccommended jet in, you say they gave you a 165 with pipe..As long as you dont have any air box mods that would be good starting point....

 

Ok cool. Thanks.

 

Hello. I just put the same pipe on my 04 Z400. The 165 main seems to be just about right but I'm at sea level. I'm running an Noss Machine intake with a Uni filter and lid removed.
Your stock main is a 130. I would go to a 140(Mikuni) or a 146(Dyno). 4500ft might be a bit skinny for a 165 main.

 

Thanks for the info Mars.[img]i/expressions/face-icon-small-cool.gif[/img]