I have a 2003 Prairie 650 with Dyna CDI, Napa intake, Twin air filter, .030" shim, EPI black secondary. Seeing as I have opened my intake up, but do not want to modify or replace my exhaust, do I need to rejet to 142,145? The machine runs great but it is hard to tell if its lean as plug chops are not very conclusive on CVT machines? I have searched for my combination but most people have done the Nyroc exhaust mod which I do not plan on doing.


Thanks Guy's

 

I would say check the pipe you are looking for a medium charcol color inside. If you are lean it will be closer to white or lite charcol. Also if you are lean your bike will run hotter than usual. If your fan is running alot, pipe color is closer to white than charcol, or it feels off I would say rejet. However if all is well don't fix with whats not broken, I speak from experience.

 

Sammy are you doing the Throttle Chops with the kill switch and holding the throttle open until it stops?

If you have not changed any jets I'd err on the rich side. More Fuel/More Air = More HP. At least try the next size larger jet to see if it runs better.

Also try the Dalton Orange Blue primary, guaranteed to put a smile on your face.[img]i/expressions/face-icon-small-happy.gif[/img][img]i/expressions/face-icon-small-happy.gif[/img]