ok,i have read this forum alot, first time posting.i have a 02 praire 650 that i just had in the shop and thay rejetted to 122.5(so they said) now it has 1500 miles on it and it started sputtering at 45 and up i have a k and n filter in it and just got the dyna cdi, it runs like a rocket with the dyna in it have had it up to 63(it runs much better than it used to evan with the stock cdi) then backed off but when it decels i get an intermittant backfire thru the exhaust with the dyna or stock cdi. i have read and it seems that everyone is running so much richer i am concerned if i am going to hurt the motor? what are the common signs of running to lean?

 

Click on this and go down to pictures 27 and 29 and see if your plug looks like this. If it does you may be a little lean.