Carburetor Rebuild; Check Ball Removal and Installation

NOS Solex 30 Pict-1 Carburettor

When people tell me that they have “rebuilt” a Volkswagen carburetor, but that it still doesn’t function well… one of the first questions that I ask is: “How many balls did you find?” The usual answer is: “None!”

That’s a good indication that a carburetor was not rebuilt properly. Disassembly of all components is extremely important. Even the tiniest foreign particle that is allowed to remain somewhere in a carburetor can plug a jet or other orifice.

First Check Ball

But, how to remove that pesky round brass plug-in the corner of the carburetor’s bowl? That’s where one of the 2 check balls for the German Solex 30 Pict-1 carburetor is located. (Note: there can be as many as 3 check balls in other models of Solex carburetors)

In the 1970’s a VW specialist let me in on the secret to removing this plug.

Looking down into the opened carb bowl, you can see the small, round brass plug-in the corner—on the accelerator pump side of the carburetor.

’67 Volkswagen Beetle — Carburetor Rebuild; Check Ball Removal and Installation

Looking into the drilling from the accelerator pump side (with the accelerator pump removed) you might be able to see the glint of the check ball that is captive beneath this brass plug. Its function is to allow gas to pump only one way–from the bowl on its way to the injector tube (also called the accelerator pump discharge tube).

’67 Volkswagen Beetle — Carburetor Rebuild; Check Ball Removal and Installation

The brass plug-in the 30 Pict-1 has been tapped (4mm x .7). This has a reason. It allows for easy removal by the re-builder. (Note: some other models of carburetors, even into the very early ’60’s, were not tapped)

What is necessary for removing this brass plug is a tail light lens screw. If you do not have one, beg, borrow, but do not steal, one from your local VW specialist.

The screw should come from at least a 1968 or later Beetle tail light lens and must be long enough to extend from the bottom of the carb bowl and well past the edge of the opened bowl. I like to use a fairly long one so that it can be used with several models of carburetors. It would be great to be able to use one from a ’67 Beetle lens but, unfortunately, those are too short for the purpose.

Try to find one that is about 82mm in length–measuring from the top of the screw head to the very tip (about 3 1/4th inches). You will note that each tail light screw has a self-centering tip that is not threaded (about 2 1/2 mm or 1/8th inch in length). This tip must be removed so that the screw will bottom when screwed into the brass plug. Carefully remove the tip right to the threaded portion but do not get into the threads or you will be unable to screw it into the plug. The screws are fairly soft metal and can be ground using a file, although using a grinding wheel is much faster and easier.

’67 Volkswagen Beetle — Carburetor Rebuild; Check Ball Removal and Installation

Now, you are ready to screw the tail light screw into the brass plug. Use a Philips Head screwdriver to do this. You will feel it when the screw bottoms. Make sure that the screw is firm in the plug but do not over-tighten it.

’67 Volkswagen Beetle — Carburetor Rebuild; Check Ball Removal and Installation

Now, place something on the edge of the bowl so as not to mar the mating surface when you pry on the screw. Using a pair of dikes or other appropriate pliers, pry upwards. The plug should pop out.

’67 Volkswagen Beetle — Carburetor Rebuild; Check Ball Removal and Installation

But…should the plug be stuck, have someone to hold the carburetor on its side. Get a firm hold on the screw with pliers or a pair of dikes. Using a small hammer, whack the dikes away from the carb and the plug should pop out.

’67 Volkswagen Beetle — Carburetor Rebuild; Check Ball Removal and Installation

’67 Volkswagen Beetle — Carburetor Rebuild; Check Ball Removal and Installation

Invert the carb over a container or shop cloth and the check ball will fall out.

’67 Volkswagen Beetle — Carburetor Rebuild; Check Ball Removal and Installation

When you have completed the cleaning of the carb and are ready for reassemble, simply drop the check ball into the hole. With the tail light screw still firmly screwed into the brass plug, install the plug. Gently tap on the screw head with a screwdriver handle or some other light-weight tool until you “feel” that the brass plug has seated. You will be able to “feel” the difference in resonance when the plug has bottomed. Unscrew the tail light screw and put it away for a later rebuild.

Second Check Ball

Now for the second check ball. This one is a very tiny ball that is located inside a long passage, again on the accelerator pump side of the carb. This passage is critical for gasoline passing from the accelerator pump to and through the injector tube–the brass tube that seats into the carb’s edge and squirts gasoline downward into the carb’s throat.

The key to removal of this check ball lies in the removal of a tiny brass pin–also located on the accelerator pump side.


Using a pair of good needle-nosed pliers or a pair of dikes, gently take hold of the brass pin. I find that using dikes is the best way. However, do not pinch hard or you will cut the pin–it is very soft metal. Gently pry a little at a time, with each pry, moving the dikes closer to the carb’s side for a good prying point. Try not to mar the pin! Eventually, with care, the pin should remove.

’67 Volkswagen Beetle — Carburetor Rebuild; Check Ball Removal and Installation

The ball is going to exit from the hole in the rim of the carb where the fuel injector tube was located. Turn the carb upside down over a container or shop rag and allow the check ball to fall out.

’67 Volkswagen Beetle — Carburetor Rebuild; Check Ball Removal and Installation

’67 Volkswagen Beetle — Carburetor Rebuild; Check Ball Removal and Installation

I have found some of these tiny balls to be stuck. With the pin out, a blast of compressed air into accelerator pump drilling, thumb held over the bowl check ball opening, should do the trick. However, be forewarned that you should hold a rag over the exit hole on the rim, because the ball will be shot out at high speed and could otherwise be lost. If you still are unsuccessful in removing the ball, even after the pin has been removed, try soaking and then use the compressed air.

’67 Volkswagen Beetle — Carburetor Rebuild; Check Ball Removal and Installation

In the case that you are unsuccessful in the removal of the pin retaining this check ball in its seat, go ahead and soak your carb in cleaner. It is likely that with the larger check ball removed from the carb bowl, you will be able to remove any remaining debris by washing and blowing the carb clean. I have had to do this on occasion. When the carb has been blown clean and dry, you should be able to hear the tiny check ball moving as you shake the carb–even though the pin is still in place

If you have been successful in the removal of this tiny check ball and have completed the cleaning process, installation is the reverse–drop the tiny ball back into its orifice. It will “seat” itself.

’67 Volkswagen Beetle — Carburetor Rebuild; Check Ball Removal and Installation

With the carburetor sitting upright (as it normally would sit on the manifold), insert the brass pin and lightly tap until you can “feel” it seat. Once the pin has been installed, by shaking the carb, you probably will be able to hear the check ball clicking in its seat.

’67 Volkswagen Beetle — Carburetor Rebuild; Check Ball Removal and Installation

A final note: The check balls are highly polished—some a golden color and some, silver colored. After cleaning, the check balls still should retain their extremely shiny appearance. If a ball is oxidized and cannot be cleaned by soaking and rubbing clean with a cloth, it is best to cannibalize another carburetor for a good one. The key to good seating is a clean carb and good, clean check balls.

Happy Motoring!
Photography by Neva Salser

Posted by Jay Salser

My wife, Neva, and I have been driving and working on VWs since 1976. In fact, we raised our family in these cars. Now, we are retired and enjoy VWs as a hobby. The ’67 Beetle always has been our favorite year. We own a '67 Beetle and a '68 Karmann Ghia.

  1. Fantastic article, Jay!

  2. Great info Jay!! Can you please reccommend an approved rebuilder in the San Francisco Bay Area? One that you know will follow all the steps you mentioned. If there’s no one locally you can reccommend, please let me know who I should consider sending my carb out to (and to one who won’t break the bank:). Thanks Jay!

    1. Michael,
      None locally. I’d give Vintage Werks or Volksbitz a try. Both are fantastic.

    2. Good afternoon, Michael! Glad that you like the article.
      For some who have been working on carbs for years, it’s very elementary. Here’s hoping that it will help others. Eric covered the bases for Carburetor rebuild and restoration. Both of the shops which he mentions do high quality work. We recommend NOT cutting corners since the carburetor is sort of like the human heart–you want it as “healthy” as possible! jay

      1. Hi Jay
        this article is a killer, 3 years ago i did my 1st carb rebuild and i was thinking that it is all about gaskets and surfaces grinding (thinking to my self “well it is probably all about that and no more”), than i have learned regarding the shafts bushings replacement and now this…… but one thing is for sure, i don’t think that this is probably all regarding carb rebuild (-:
        JUST ONE IMPORTANT QUESTION: WHAT IS THE SIZES OF EACH BALL ? (i will be more that happy if you could recommend on a seller that sell a good quality of this balls

        1. Jay is a wealth of knowledge!

        2. Good morning, Shay…thank you reading the article. always is an eye-opener when dealing with these simple carbs only to learn something new–every time I open one! I do not have a handle on the sizes of the check balls. I recommend that you contact Tim Robson @: 360-894-8787. Or e-mail Tim @:

          Tim is a Solex Carburetor Specialist. He knows them backwards and forwards.

          The original check balls usually are re-usable. I toss them only when they are corroded.

          Keep up the good work!


  3. What a great article! Thanks Jay.

    1. Tom…it’s our readers who spur us to get these articles and tips published. Many thanks for your encouragement! There’s more to come! jay

      1. Jay Salser! A true partner here at

        1. Hey…cut out the sweet talk–I’m gonna cry! The truth is–I’ve never had so much fun! The icing on the cake is getting to know all of the great people in the ’67 Community! jay

          1. *Cracks whip. Fine, get back to work!

  4. Hello, Hank…Thanks for checking in!

    Most of the 28 series carbs for the Beetles have the third check ball. It is part of the Power Fuel System. For Ghias and Buses–most did not have this check ball during the 28 series run [28 Pict and the 28 Pict-1 (2)]. The third check ball is located beneath the brass plug located on the rim of the throttle body (lower half of the carb) on the throttle lever side of the carb. Once the brass plug is removed, the check ball is immediately visible.

    I do not know the reason for the Beetles to have the check ball and the Bus and Ghia usually not. Notably, the Bus and the Ghia always had a larger air correction jet than did the Bugs. There may be some correlation here. If I learn, I’ll let you know.


    1. Hendrik Blommers December 21, 2013 at 6:14 am

      Hi Jay,
      Thanks for following up on my “third check ball” question. Now to pull a carb and check out thus new information. Best wishes for a Merry Christmas.

  5. You are awesome Jay, nice article, real Macgyver moment there with the lens screw. Jay, Eric have a great Christmas and a happy and fruitful new year to you and your families. I must get writing some more articles, it takes it out of you moving somewhere new but i’m getting there slowly.

    Thinking of an article on yearly vehicle inspections from around the world.

    I understand that in the US you didn’t have them apart from smog check, in some countries in Europe anything modified is banned and the car has to be as it left the factory even down to its original radio!!

    Merry Christmas Guys

    1. Hello, Matt…It’s good to hear from you!

      Here in Texas, if a vintage vehicle is registered as an Antique/Classic Vehicle, it becomes exempt from the otherwise yearly inspections. Even if left to the conventional registration, if a vehicle is 25 years or more old, it goes through a very limited inspection (tires, brakes, horn, lights-turn signals and wipers–no emissions).

      Thank you for the Christmas wishes! I wish you and yours the same. May your new residence prove more than satisfactory and may you have Good Health and an Enjoyable Life during the New Year!

      See you “down the road”!


    2. Matthew,
      Thanks so much!

  6. Hi
    Excellent write up
    Please post the sizes of the balls.
    I lost the injector tube ball.
    Thank you in advance

    1. Hello, HM…thank you for contacting! To bring other Readers up-to-date, HM, Eric and I communicated via separate e-messaging to solve this situation. As it turns out, HM, who lives in South Africa, was able to find a parts carburetor (34 Pict-3) which had a usable check ball. With this spare in hand, he has been able to complete his carb rebuild. Good news! jay

  7. I recently rebuilt the carb on my ’68 bug, and I’m afraid I scratched or warped the brass pin that holds in the second check ball, so now fuel leaks out around the pin when the accelerator is pressed. Nobody sells that part and I don’t want to have to buy a new carb just for that little piece. Does anybody know a good fix?

    1. There is nothing particularly special about the brass pin so making a replacement shouldn’t be difficult. Measure the diameter of the pin and see if it corresponds to a standard wire gauge (say 10 gauge or 12 gauge copper wire) and, if it matches, use it. If not a good match, get a piece of copper or brass a little larger in diameter, chuck it in a rotary tool (like a Dremel), and sand it down to a nice interference fit.

      1. I was in a hobby shop today purchasing some 4-40 X 1/2″ cap head screws in order to repair a 1960 VW dashboard light switch. I strolled around just to see what else they sold just in case I need other little bits and pieces in the future. I happened to notice they sold all diameters of brass rod. Maybe that’s also an option for those that need to make small brass bits.

        1. Hello, Hank…Thank you for this observation! Indeed, this would be a good option. I have, in fact, fabricated the pins from brass cup hooks–straightening them, then reducing (by any means available) to OD size, then length. jay

          1. Look for a brass tack or very small brass nail to replace the pin if necessary. Measuring the pin diameter with metric calipers would also help.


      2. Hi, Larry…I agree. And your idea of using the Dremmel Tool to size the pin is a great one! I would not use copper because it is too malleable. The brass is harder and, thus, more resistant. If you examine one of the factory pins, you will note that the end which is inside the drilling is tapered. Perhaps this is to allow
        better passage of fuel past it (?). jay

  8. Thank you for this article Jay! I have one question about the second check ball. What exactly is it’s purpose? I ask because my accelerator pump injector drips when parking my bus after driving it. It’s slight, but leads to flooding.

    Thanks, Jerry!

    1. Jerry…Here’s a Reply–although, for some reason, the Site did not advise me of your Question–so this is VERY late. When the accelerator pedal is pressed, the accelerator pump diaphragm is deflected directly by the throttle link. This causes the 1st check ball in the bottom of the fuel bowl to close so the “charge” of gasoline is directed toward the 2nd check ball that is in line with the pathway between the Accelerator Pump Chamber and the Spray Nozzle.

      When the pressure lifts the 2nd check ball, the gasoline can go on by to the nozzle. Once the pressure of the spray is exhausted, the 2nd check ball drops back in place sealing the nozzle from further flow and making a sealed “chamber” of the passageway. When the throttle is released, the Spring in the Accelerator Pump Chamber opens the 1st check ball so that fresh fuel can enter the accelerator pump.

      Now the Chamber and passageway are full of fuel, ready for the next accelerator pump shot. jay

    2. Jerry..More than likely, it is not the check balls which are the problem. It is parking on a slope–engine on the downward end or it could be that the bowl float valve (needle valve) is faulty and does not close completely–thus allowing fuel to overfill the bowl and then to drip out the overflow into the carburetor’s throat. Also check your fuel pressure to see if the out-put is too great. It should be about 2.8 psi or thereabouts. If too high, the pressure will over-power the needle valve and over-fill the bowl–resulting in gasoline getting out of the bowl through the over-flow tube and thus down the throat of the carb–flooding the engine. jay

  9. Hi- Just seeing this and hoping I can get some feedback (February 9, 2021). The plug on the larger check ball on mine is 1) not threaded and 2) solid (maybe hard plastic). Seems like it was designed not to be removed. Any thoughts on this? One person on the Samba seems to say just clean the hole where the ball is with BRAKE cleaner, from the accelerator pump side and don’t try to remove it. Another seems to say put a largish pin in the hole and lever upwards (seems like a risky thing to do). TIA for any help. (EMPI Pict 34 carb, BTW, probably from 2017 or thereabouts).

    1. Brian,
      Don’t know why it says that the plug in the bottom of the fuel bowl is threaded; it is not threaded. I think what was meant was using the screw to thread the screw into the plug. The plug has a hole in the center and this is what gets threaded.

      On your carburetor, does the plug look solid? If so some of the rebuilding kits come with a replacement cup-shaped plug. What you describe could be the brass plug but with dried sludge and varnish on the opening making it look solid.

      Go here to see a cross-section view. In the lower right corner is the plug and ball. You may have to drill the plug to pull it out. Use a drill that is the same diameter as the end of the long tail light retaining screw. The drilled hole should be slightly smaller that the threaded shaft of the screw. Preserve the plug so that you can measure the OD. Then see if you can find that diameter in brass rod from McMaster-Carr, Grainger, or a hobby store. If you cannot find anything look on Amazon. I am sure McMaster-Carr will have what you need.

      Paul Villforth

      1. Brian,
        Forgot the link: Look for the 34PICT-3 sectional view.


      2. Hello, Paul and Brian. Thank you both for commenting and critiquing the Article. You are correct when you say that the plug is not threaded–the plug, in other words, does not screw into the hole in the bottom of the carburetor bowl. However , I’ve not seen a German Solex 30 Pict-1 (VW 105-1) which is not threaded so that a screw cannot be screwed into it. I have found that the later H30/31 Brazilian Solex carbs do not have a threaded opening into which the Tail Light Screw can be screwed. I also have found those which have a solid plug–which, as you say, must be removed by drilling into. I have found all Solex Plugs to be of the same size. There are lots of these in most CarbGuys’ parts bins from carbs which have had to be scrapped. If ever you need one, contact me for a free plug which has the threaded portion. The threads are 4mm X .7, by the way. I find that most of the plugs (in Solex carbs) have the recess, even though it has not been tapped for threads. When tapping, be sure to grind the tip of the self-tapping tap so that it is now a “bottoming tap”. Keep reading from jay

    2. Hello, Brian–Thank you for commenting on this article. Remember–this article is very pointed to the VW 105-1, 30 Pict-1 Carburetor for the 1967 Deluxe Beetle. It may or may not apply to other Solex Carburetors (as I comment below to Paul’s response). And, it certainly does not apply to “EMPI” products. Remember, is pointed to just that–the 1967 Beetle. jay

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