Thermoquad tuning on 318

AJ,
Tug the dist until the idle speed no longer increases....& that is what the engine likes. Your words....& they are correct. In total agreement. It is also the correct timing for THAT engine. There is no compromise for the correct amount of idle timing. If the timing is changed, then it has been compromised...& it was a bad move.

Sorry, more misinformation. If you get detonation, you put stronger springs on the dist weights to delay ign advance. You do not reduce idle timing.

Reset idle speed with timing? Don't think so. The number of turns out on the mixture screws is going to be a product of idle timing, idle vacuum [ cam size ], engine size ...& the carb itself. Don't know where this magic number of 2.5 turns comes from. The number of turns will be whatever provides the smoothest idle. What is imperative is that 0.020-0.040" of t slot is exposed at the desired idle speed with the correct idle timing. This is how the carb is designed to operate & provide the correct see-saw action of T slot operation for a smooth off transition from the idle cct to main cct.
Some combinations will require bypass air to achieve this.