and if you like Tom and Ray, we stumped most of the chumps (including me), but the right answer came from:
WrenchBender retired.
(ta dah! yay! applause!)
The key was the backfire I heard. Today I started in on it again on the assumption that the condenser was bad and that I have seen that problem before with similar results - only once - but sometimes I have a memory like an elephant.
Put in old points and old condensor. No real change. So I opened up the carb to see if the floats were ok - and they were. So that wasn't it. Carb was recently rebuilt.
So, then I sez, hmmm...dat ain't rite. So I put a vaccum gauge on the distributor vaccum feed line - 8 psi. Dat ain't rite. So I start looking at the various lines. Power brake line was fine, but when I checked the PVC valve line, it was ok at the valve cover, but, the press fit nozzle on the manifold was loose! Dang it!
Stuff a bolt wrapped in plastic on it, bingo, adjusted timing back to 4 btdc, 550 rpm, rock solid. I knew it had run correctly for a while, and so that was what was stumping me. How could valves or carb go to manure mode so quick? Couldn't. Only bad thing could be bad points or condensor, or, as Wrenchbender sez, vaccum leak.
Now I just have to figure out a new press fit nozzle for the PVC valve, or tap in a new barb. I am relucant to tap because of swarf getting into the engine, so I might JB weld or see what else I could make.
