by WillCRF » Wed Dec 07, 2005 11:48 am
Mike,
You are correct on how to check the plug by using the kill switch at different throttle positions. As far as the screw on the bottom, that is the fuel screw. The screw on the side of the carb addresses the idle.
If you add a larger pilot jet, you will have to adjust the fuel screw on the bottom. The pilot jet and fuel screw work in tandem to control fuel from zero to about 1/4 of the trottle travel. By adding a larger pilot, you need to reduce the amount being provided by the fuel screw. This is done by turning the screw in or clockwise. I kept turning mine in little by little after adding the new pilot until I got good crisp throttle response off idle.
Overall the modifications I made to my younger son's bike (pilot, main and airbox) has made the trottle response much better. There is a lot less hesitation or throttle lag. Now my other son is on my case to bring his XR100 up to par with these modifications.
Let me know if you have any additional questions. Good luck.
Will
'05 450x (Rekluse)
'07 KTM 250XC-W (Rekluse)
'05 KTM 200exc (Son #2)
'06 KTM 200xc (Son #1)