if i didnt come across this in a couple books it never would have occured to me.. and it took me a long while to understand what the they were saying.
So many tuners in another forum are fixated on jetting. Larger jets are the name of the game. Why? Because when they add an expansion chamber, plug chops suddenly show a lot of heat up in the power band..
Nobody wants to retard their timing .. I guess the word 'retard' or 'retarded' is uncomfortable. So, drown the heat caused by too much spark-advance with more fuel and run way too rich. At least nothing got 'retarded' ;)