Yep, I have some old iphones as well as go-pros that I can put in there to see what's going on. I didn't the last time it was out, but I'm thinking of going out without the engine hatch on so we can see what's up a little more easily.

Any thoughts about the vacuum readings? They look okay to me - nothing too far off from one another.

Tom,
I found your problem. You can thank me later...

Hahaha… Thanks!

Not really. So many little things that can make manifold vacuum slightly different.

Did have a random thought abt the power valve... AFAIK, most carbs have a check-valve to protect the power valve diaphragm form excessive pos press spike during a back-fire event. My old carbs don't have the check valve and if I get backfire during start-up, it blows at least one of the power valves out. So if yours have a check valve, make sure it's not stuck closed blocking the vac signal.

Thought about that one… the trouble is that if vacuum is closed off, the pv will hang open and allow more fuel.

Doh!! You are correct. It was past my bedtime last night.

Haha! I had a similar response in the original thread I posted about the carb being off. Glad I’m not the only one!

Alright. Both carbs are back on the bench. I took everything apart and have somewhat of any idea of why these things have been problematic.

The vacuum source for the PV’s on both carburetors were never drilled. The PV’s were never working to begin with. I’m not sure how I missed it - I guess I just assumed they were drilled in a different manner (connected to another vacuum channel perhaps). Nope - I fished through every hole to make sure there was no trash anywhere.

What a waste of time.

For now I’ll baseline the carbs back to 86 and 93 and see what it does (it has 84 and 90 jets now). PVCR is opened up to .063 from .059. We’ll see where we end up. The original combination seemed close with the 86s and 93s at wot.

Is this the vac passage in the main body or the fuel passage within the metering block from PV to booster circuit that wasn't drilled?
If it's the vac passage in main body, wouldn't the PV be ON all the time??

Here's a pretty good video on Holley power valves. It's geared more towards cars but he explains the operation pretty well.

It was the vacuum orifice in the baseplate. There was nothing making it to the PV.

I dropped a lot of main jet and that messed the whole thing up.