Popping Exhaust

[rip]

I'm not convinced that 16degrees btdc is always correct (depending on the modifications).
Once you have set your base timing, why not mark it then experiment? With your 'correct' timing marked, you can always reset it again later if you make negative changes.

[max and andy]

We haven't had any popping from the Piper. But the tone is getting deeper and sounds great going under bridges. We had the timing and idle set a few weeks ago. Its running sweet still but we have noticed its not quite as sweet as when first adjusted. Plus it doesn't start as quick. Still good but not like it was. Just touching the key and you where away. Could the timing need fine tuning so soon after being set? And what is the norm for intervals between setting? A&M

[rip]

I believe some check timing once a month or so, but you can check timing as often as you like. I hardly ever do mine at all.
Ideally you need a timing light & also to know where it should be set to get the most from your engine (which should be 16degrees BTDC), then you can do it yourself as often as you like. The alternative method I chose this time was to tweak it until it feels good, using a standard test (I chose 30-70 in 4th on a flat road). Now I know what it can do, I can perform this test from time to time. Now I know how long it should take, I can judge whether or not I need to fiddle or not.

[RayD]

Rip,

What did you find is the ideal timing?

Do you imagine the ECU only moves the timing a certain amount from where it's set, as opposed to setting it to suit the conditions?

In other words ... if you start at 16º and under certain conditions the ECU would adjust it to 40º ... do you think that by starting at 20º it would adjust it to 44º instead?

Ray

[rip]

Ray,

We seem to be drifting , this thread was about exhaust popping & has turned into one about ignition timing.
How about we pick it up in this thread which is about timing in the first place?

Terry can have his thread back now

[tte200]

Status update
I have now done the base timing using the information on here (Wiki) which I found most helpful ( for which I will make a donation to LEC). Found the timing to be 5 degrees BTC now changed to 16 degrees BTC result is the car now runs much smoother and responds better, but more importantly it seems to no longer pop..but has not solved the starting issue.

Thanks to everyone for helping point me in the right direction and for the information required to do the base timing.