In my Johnson manual, 1990 90 Hp, on page 1-36, there is a section called, "Cam Follower Pickup Timing". In that procedure, it tells me to move the spark advance lever until the cam follower is aligned with the center of the mark on the throttle cam. I have done that, but I don't see how the 'spark advance lever' has anything to do with the spark advance when it is controlling the throttle cam and is not even hooked up to the timer base! The only lever that is hooked to the timer base is the 'spark advance rod'. So, is the purpose of the 'spark advance lever' to get the embossed mark aligned to the center of the roller? Next in that procedure, it states for me to adjust the wheel on the 'spark advance lever' to mess with the timing. Won't this just open or shut my carb while I'm at idle? Shouldn't my carb be closed at idle? Why do they want me to mess with my carb position at idle? If I move the thumbscrew on the 'spark advance lever' then it moves the embossed mark away from being in the center of the roller, which is not where the roller should be at idle.