1973 super beetle 1303S, 1600 cc engine or carburetor proble

[cepgap]

Dear friends, I am new here on the bug world. I bought a beetle before 5 days ago and realized that this beetle has problem on the engine or on the carburetor (maybe somewhere different from the engine or carburetor).

https://www.youtube.com/watch?v=kYtaoeNnO5A&list=UURgwT6XscEINnnx2oaz16qQ

To understand what I mean please watch the video which I captured and if somebody knows the source of the problem please tell me what to do.

Thanks a lot,
Regards
Serdar

[Randy in Maine]

Are there any good local mechanics around you that can show you how to adjust the valves, the points and the timing?

[cepgap]

[Tim Donahoe]

You seem to be advancing--eventually.

When you pull hard on the accelerator arm, you eventually get a nice strong burst of power; so I don't think it's a timing issue--or valves.

But, you need to adjust those valves regularly, anyway.

My best guess is the carburetor. You're not getting fuel from the accelerator pump--intially.

Take the carburetor apart and clean it well. Then blow out all the orifices with compressed air. If possible, have a good mechanic rebuild the carburetor.

Tim

[Aussiebug]

cepgap, welcome.

To get the engine to spin up smoothly, you need some vacuum advance from the distributor, and extra fuel from the accelerator pump in the carburetor.

That distributor should have both vacuum and centrifugal advance, so it gets advance from both the engine rpm and the throttle position.

First check the operation of the vacuum advance, because it sounds to me like you are NOT getting any vacuum advance as you open the throttle - only centrifugal advance as the engine rpm increases. Take the distributor cap off, and then remove the rotor arm, so you can see the points-plate underneath. Pull the vacuum line off the left side of the carburetor (near the throttle arm) and suck on it while you look at the point plate - the vacuum arm should pull the points plate anti-clockwise about 5 degrees, and if you seal the vacuum line with your tongue, the points plate should stay there and not drift back to it's rest position. If it does all that, then the vacuum advance is working OK.

Also check that the accelerator pump is working. Take the air cleaner off the carburetor and look down the throat. Pull the throttle arm out quickly and you should see a nice squirt of fuel go down the throat. If it is only a dribble, then first try to get a bigger squirt using the cam adjuster on the linkage on the right side of the carburetor. If that does not help, then the accelerator pump on the right side of the carburetor needs attention. Rebuild kits are available. The squirt of fuel should go straight down the throat and not splash on anything - you can carefully twist the delivery tube a little if needed.

Several other things to think about too.

The position of the fuel filter is bad. It should be BEFORE the fuel pump, not between the pump and the carburettor. The reason is that the brass inlet pipe in the top of the carburetor is just a push-fit, and after 30+ years it can jiggle loose with the weight of the fuel filter hanging off it. The other reason is that putting the fuel filter BEFORE the pump, it means the fuel pump gets nice clean fuel to pump with, so the valves inside don't wear out.

There is a paper pipe missing off the air cleaner. This runs down to the right side cylinder head so the carburetor gets warm air when the engine is cold. With that missing, the hole in the tinware at the rear of the engine (rear means rear-of-car) allows hot used cooling air from under the car to get back up into the upper engine bay, and the fan will suck that hot air into the fan, so the car is being cooled with some hot air, which its not good. Even if you don't connect that air cleaner warm-air pipe up, close off the hole in the tinware with a piece of tin and a tek screw, so it can't leak air.

The metal vacuum line from the carburetor to the distributor vacuum canister SHOULD have the shape of an inverted J, so it comes out of the carburetor and turns upwards under the air cleaner before turning downwards to the vacuum canister on the distributor. this stops any fuel in the carburetor getting into the canister and destroying the diaphragm.
This image from the picture gallery shows you what it should look like

And you might find this article on our site useful - it is a complete tune-up guide for your car - valves, carburetor, timing and so on.

www.vw-resource.com/34pict3.html
_________________
Rob
Rob and Dave's aircooled VW pages
Repairs and maintenance for the home mechanic
http://www.vw-resource.com