Q&A for How to Set the 34Pict/3 Carburetor on an Aircooled Volkswagen (Vw) Beetle

I had the same issue. First, make sure you adjust carb after the engine is warmed up per the directions above. The "Volume Control" jet is usually the issue when it does not idle correctly. Make sure it is not more than 2.5-3 turns out, but less is better. If you hear any backfiring, even the slightest, the volume control jet is out too far and dumping too much fuel. Check the "O" ring on both "by-pass" and "Volume Control" jets. As you adjust out, the tightness should be consistent, otherwise the "O" ring is bad.

You may want to check your hoses and connections for a vacuum leak. You'll lose power. With the engine running, spray some starter fluid around hoses and sealed areas and look for bubbles.

Make sure your accelerator pump is working, if there's an adjustment adjust it so you get a good strong stream coming out. Make sure you have power to your air bypass valve, and look for leaks at the intake gasket. You might even have your float set too low, make sure it is at the top of the bowl, usually one thin copper washer under float valve. Yes, you will probably have to take it off and apart, it's easier on a bench. Check volume screw (small one) is out about 2 1/2 turns and the big screw bypass screw about 1 1/2 turns. Put it back on. It could be a lot of things, as I didn't even mention the choke or vacuum leak. But make sure she squirts first and foremost. If you still can't find the problem, take it to a mechanic.

Sounds more like you have a blocked idle channel or jet. You may be able to adjust it to run properly, but once the trapped debris breaks free, you'll have to adjust it again. I recommend removing and cleaning the carb, and change the air and fuel filters. Idle speed and mixture should be adjusted with the air filter in place.

You are timed to the wrong cylinder. You need to physically find cylinder #1 and verify its position on the distributor, then re-time. Take out spark plug #1. Find a piece of good tubing - soft fuel line is perfect. Make sure it's in good shape, you do not want anything falling off in the cylinder. Stick the tubing down the spark plug hole. Hand crank the engine counterclockwise until you feel the cylinder coming all the way up (TDC). Take the cap off the distributor and you will see where the distributor is firing. There are a hundred reasons why this may not match any diagrams. Then from that point, make sure it's in correct firing order: 1-4-3-2. Reassemble and re-time.

Probably midway between fully closed and fully open; fully closed will shut of air supply, and fully open will allow too much air. Aim for an initial running rpm of about 1000; this should put you in the ballpark for volume screw adjusting.

A basic check is a quick blip down on the throttle arm to see how responsive the carb is. Any hesitation, missing or backfiring means you have to check your settings again. No carb settings should be done unless the basic plug gaps, points gaps, timing and valve settings are correct.

It should be good and warm, but not hot enough to burn you. Generator is also part of the cooling system, and drives the fan. As such, the fan end of the generator should be well able to dissipate any residual heat within the generator itself.

Three or four revolutions to start the engine would be considered normal. Three or four starting sessions would point to some issues in the starting circuit - probably dirty plugs or no points gap. If the engine makes absolutely no attempt to start, it may also be a petrol issue.

Your air/fuel mixture is set wrong on the carburetor. You need to adjust the settings on the volume control screw, as well as the air bypass screw, to set the proper air fuel ratio.

Typically one is 12 or 10mm and the other one is 8mm.