I agree with the above comments. However on simple non turbocharged aircraft engines a lot of engines are equipped with a single EGT probe for one cylinder. Certainly not as good as a system that has probes for all cylinders but much better than nothing. Lean the mixture until you are at max EGT then enrich the mixture to drop the EGT reading around 100 degrees . I'm not trying to make a big deal out of this, just thinking out loud and wondering if I have a tool to possibly simplify achieving the best mixture for a mildly modified street engine. Lawre, I would like to see the numbers that your data logger give you. Is the engine running gas, alcohol, or other racing fuel? Thanks for your offer.