Miss above 4000 rpm

[Texasdoc]

Here is one of my plugs. They all looked the same. I've checked the continuity of the wires. I made sure the wires were securely plugged in on both the cap and plug side. Firing order is correct. Wires for adjacent firing plugs are not run side by side in the looms to prevent crosstalk. No sparking when started in the dark. I wasn't able to check it tonight as I would like to keep my neighbors.



The plugs are so new, there isn't much color to them. Still have the gold color. The bases of the cathode tips/cage are slightly black. No tan color, no black soot, no wet oily appearance.

Originally Posted by Rick Parker

You may be pulling in too much advance and cauing some cross fire within the distributor cap (if it is small diameter).

I thought about this. This is why I retarded the ignition so I would only get 38 max with base, mechanical, and vacuum at 4000rpm. Maybe I should get one of the adjustable MSD rotors to make sure the cap is in phase.

I also found this thread clicky that discusses a similar issue. One fix was a new carb vs. carb tuning. Another thought was sparking wires (checked that by running the engine in the dark). The other thought was plugged fuel filter. I have two of those see-thru glass fuel filters: one between the tank and the electric pump, and the other between the pressure regulator and the carb. Both look clean.

I will try to drive it again tomorrow to see if playing with the plugs and wires "fixed" something.