[westofb]

I still stand by my confirmed statement, I agree with Matt that you could be a tooth off in either direction and still get them to open as the s mark moved into the window. However, if you cam was in wrong, one tooth off, you would have one of two senarios. One tooth off in one direction would have the points rod riding on the baseline of the cam load, to get it to break in this senario, your points would constantly be open, since you are on the baseline of the lobe, they would have no choice but to be open. The second senario is that when you set them to open as the s mark moved into the window, you would already be up on the lobe of the cam (they are already starting to open before reaching the s mark), this might be hard to tell, but as the cam follower dropped back down on to the base line of the cam, you would have slack between the follower and points themselves. So if you were off in this senario, it would be hard to see slack in the follower/ points, so maybe you could be off in one direction, but I would think you could detect the slack between the follower and points if you were to look closely (may have to use a magnifying glass).

So Matt could be right if you off one tooth in the second senario, just for the fact that detecting the slack between the follower and points would be tough. In the first senario, you would never get the points to close because you set them to open on the cam lobes baseline or base circle. I hope this makes sense.