Ed, not to refute what you are saying, but I've seen it in my own engines that 'mysteriously" don't hold the proper timing at lower rpms sometimes. This "inconsistency" is most evident in the 1100-1300 rpm range, where sometimes the timing will be more advanced than others, usually on the scale of 5-6 degrees. This condition is always accompanied by roughness and the engine seeming to "hit" harder with each power stroke.

According to Keith, and I believe it from my own readings, the timing chips in the CH ignitions can start advancing the timing as low as 1200-1300 rpm, and if so this would account for timing differential at the "borderline" point for timing advance (or lack of retard) to occur. A simple thing like a tiny change in magnetic field from the permanent magnet, due to heating up or a small change in air-gap because of temperature changes, COULD be enough to affect the "dwell" time seen by the processor. After all, the processor senses the magnets speed and position as it passes the pickup, does it not? And then does a comparative search based on how many times per second/minute this is occuring to determine actual rpm and position of the crankshaft, THEN institutes the proper retard/ignition point from the programmed timing curve. Correct?

You had better believe I would not put it out on this list unless I had that sort of information directly from the source. The fact that you are helping out with this timing hassle is to be aplauded, Ed. I for one, really hope you guys get it straightened out.

As for logarithm vs. Algorithm. . I stand corrected. . .Oopsie, gee golly, I made a goof up. somebody please crucify me for making a mistake at OH-dark-thirty when my brain was only firing on 3 cylinders.

One thing to remember, Ed, Keith is not allowed to make announcements of that sort on this forum (didn't we just have a poll that said people didn't want manufacturers using RCU as a Sales Bazaar???) And if, in all the discussions I have entered in this forum I make one or two mistakes, I'm sure it's very few and far between. Excuse me for being only human, . . it happens sometimes.