My buddy has the perch adjuster on his and he gets a pretty good amount of drag at idle when he adjusts it to engage right above idle. Could it be that his clutch cable is a little sticky?
It could be the clutch cable. I tried a new cable with mine, but it was still inconsistant. One thing he can try is snapping the clutch lever open and closed. By this I mean pull it to the bars, then let it snap back open. This will sometimes get rid of the resistance from the whole cable/perch adjuster setup.