May 2nd, 2012 02:23 PM
Also, it should be known that there is no such thing as a timing light that is "correct."
They are just like O2 sensors - each has their own personality (mechanical or electrical delay, in this case). The whole point of timing an engine with one is to use a light that produces repeatable results, then use it to find the best timing for the most power (if that's what you are looking for).
If I had a pile of ten lights, I'd expect ten different results on any engine. The only thing that matters is repeatability and consistency.