Suddenly, it's backfiring! Ideas?

[wheelzzs]

sounds like a burnt intake valve to me

 

[jahearne]

sounds like a burnt intake valve to me

or maybe one that is recessed that wore away the valve seat from the lack of leaded fuel.

 

[LaGrasta]

Well, are you ready?

The timing was off.
After a compression test (approx 150psi across the board) and a visual valve and ignition inspection, I was left with nothing obvious. I was prepared to go into the cam and timing chain. My Dad wasn't buying those as faulty parts and suggested timing it.
We set a vacume of 19, then set the timing with a light at 14° and took it for a spin. All is well.
I'm clueless as to why it started coughing the way it did. The dizzy hadn't come loose and the ignition parts are still the same. I'm not sure why the timing was off.
We didn't advance it as much as I like and it feel a bit slow, but at least it's running and not coughing or backfiring at all. I put about 100 miles on it without a hiccup.

Thank you so much for all your suggestions, help, and offers.

 

[Geezer 300]

Funny how often things turn out to be something simple

 

[cobraguy]

No S*** Sherlock. I'm sure I'm not the only one who had assumed you had pointed a timing light at it when covering the easy stuff. I can't razz you too bad though I've done worse, but towing it home because the timing was off, thats right up there. Hope your turkey was good and glad to hear it was a minor problem. Rich

 

[Anonymous]

I am glad you found the problem before all the big stuff happened. We all can learn from each other, even on the simple things. Check with a hop up mechanic as to how far you can go with the timing. That might be helpful.

 

[Stubby]

The fire was finding the path of least resistance.
I don't know how the Lodomatic dizzy is built, but I have seen some ford dizzys lose the roll pin that holds the reluctor ring in place.