i'm missing something here, 'too much retard' so it's being suggested i move the full advance forward from 34BTDC a degree or two or whatever would prove to give optimal top end performance / throttle response. But is this not done at the cost of the fully retarded position moving a corresponding amount and leading to difficult starting?
I'm sure trying to address this is the reason my ATD was in the gnarly state i found it when i took over the machine.
Too much retard is actually saying that at the fully advanced position, the ignition is too retarded - BUT your comments on the ATD are a cause to stop and fix that before you do anything else.
A while back I destroyed a piston in my Comet thru detonation - caused mainly by too much advance. And that excessive advance was caused by a faulty ATD. I did not realise it at the time, but the pivot pins in my ATD had worn/broken loose from the backing plate. I set my advance to be 36 BTDC with the ATD locked in what I thought was the full advance position but subsequently found that by applying a bit of brute force I could actually force the advance up to around 43 degrees - remove the brute force and it seemed like the advance was just 36.
I completely rebuilt my ATD, welded up the pivot pins, fitted new springs and also added some weld to the ATD ears so I could set its range to suit what I was after at the time , being 32 Degrees at full advance and 4 degrees at full retard. As I said earlier, I am about to try 34 degrees of advance with 6 degrees retarded. I can already tell you with 6 degrees retarded there are no starting issues.
SO FIX THE ATD FIRST.
Based on my personal experience with detonation, without the validation from a dyno run, I would NEVER set the advance on my Comet to any greater than 36 degrees - just my opinion.
Martyn