OK so I have a 74 Super, 1600 DP, 34PICT carb (new), and pertronix distributor(new). I've followed carb initial setting instructions, adjusted the valves, has new plugs and wires. I've never cracked the case open but have new pistons, jugs, connecting rods and heads, also all new exhaust. Here's the problem: the car starts but will only run if I keep the throttle close to wide open, as soon as I let it return to idle it dies. It appears I have good fuel flow as the see thru filter is full. Do I have a bad air leak some where or is there another possibility? I just ordered new intake manifold boots. I had the same issue with the stock dual vacuum distributor. Any help would be great as I'm pulling what little hair I have left out.

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Check the carb out to make sure the factory settings are correct(float level). Are you using the Official Bentley VW manual instructions for setting this carb? If not you will NEVER get it set right. A quick squirt from a can of WD40 or (GASP) starting fluid around the manifolds and the boots will tell you a lot in the way of air leaks.
66 Ghia, "Dexter" 76 flat window Beetle
It's not a Car it's a VolksWagon!
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I just went through the same thing.

I use carb cleaner to find the vacuum leaks. The engine will rev a bit when you find the leak. Make sure everything is torqued correctly so as NOT to strip any nuts or threads on the carburetor. 

After you tighten everything down, check again. If you still use the stock air cleaner, make sure the vacuum line from the carb to the connector on the air cleaner, the one on the right, is tight too as this will cause the engine to sputter and run unevenly.

While adjusting the carb with the air cleaner off, you need to block the vacuum line. Also tighten the Phillips screws on the rubber connectors of the intake manifold as loose ones will also cause a vacuum leak!

Let me know how you made out.

Hope this helps.  
"If the engine starts, you're half way home."
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Check your electric fuel cutoff (side of carburetor) I had the same problem with my 1974 Super Beetle. I had to change my intake manifold because of the emission crap. (it leaked) Replaced with older style after welding holes shut. Remember every time you take off the Dual port manifold ends they require new metal seals and I usually put two gaskets under the carburetor (one is too thin) and because I dont want to keep going under the hood, I pulled the brass tubes on the carburetor and plugged them with JB weld. It stops all the vacuum leaks.
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