Small Engines (Lawn Mowers, etc.): Chainsaw fuel ratio, worst case scenario, echo trimmer

Question
I just replaced the cylinder, piston, and rings on my efco 181. I would like to know the best ratio to mix the gas to make the engine last the longest. Any information is appreciated. I looked for chainsaw engine failure analysis but could not find much. It would be interesting to see a comparison of the internals of one saw run on 25:1 and another on 50:1. I have done a lot of research but everyone has a different opinion. I have heard old timers say run it rich because it protects better and worst case scenario foul a plug or plug the exhaust. I have also been told industry standard is 50:1 now and any more oil than that burns hotter and could damage the saw. I know how to adjust the carb properly. I have stihl snythetic oil. I also purchased two blue max saws that recommend 25:1. If you have any resources or links with information I would appreciate it. Thank you

Answer
Mainly opinions.  True about running more oil regarding the carbon deposits and fouled plugs.  You could run 40:1 and then adjust the carb high speed a little rich, more fuel, but you will loose high speed RPM.

I use 50:1 Stihl for all by equipment but mix it to about 40:1, just use a little over .75 gal of gas.  I have had my Echo trimmer and blower for about 17 years and both still run great.  i use the blower year round so the engine get lots of hours on it.

I've never seen any rings build up with too much carbon due to a richer oil mix but I have cleaned lots of spark arrestors.

How long did the last cylinder and piston last?

Eric