On the side of the IP you have a cam operated arm that I understand to be an advance mechanism. I have 4 IP's I can look at. All 4 activate the arm at different times and rates. Granted they are all 4 used. (2 running and 2 needing rebuilt) So my question is on a new or new rebuilt unit does this arm move immediately as the throttle opens? I notice that the cam is clamped to the shaft via a screw, can I loosen this and rotate the cam to acuate the advance are sooner or later? Ie take up the slop from being worn? Any performance to be gained by doing so?