I have a 2003 XR70. I recently replaced the fuel petcock/fuel strainer screen assembly. I am having trouble adjusting the idle. I have watched and followed the videos on this and other forums and feel that I have the air screw and idle adjustment close to good, but the bike idles unevenly and is rich as the exhaust odor is gassy. However, when I turn the petcock to the off position to allow the fuel in the carb to be used up while the engine is running, the idle becomes normal and the gassy odor of the exhaust becomes cleaner as the fuel in the carb is emptied. It seems the bike runs rich when the fuel petcock is open and it cleans up when the petcock is shut and the fuel reaches some "optimum" level as the fuel in the carb is consumed. The idle runs clean and even all the way until the carb is emptied.
Is this a float level issue? Or is a float level issue indicated by excess fuel dripping from the overflow line? I do not have fuel dripping from the carb at all.
You group knowledge is much appreciated!