While cleaning a vintage 30 Pict-1, VW 105-1 carburetor, I noticed that one of the manifold securing studs had a nut on the top side. This almost always is a sign that the threads have been stripped and that someone has put the nut on the top end so that the carburetor can be used. It is not a very effective manner for saving a carburetor. And, unsightly, as well.
This is the carburetor that is specific to 1967 Beetle Sedans and Convertibles and they are becoming more and more scarce. I turned the carb this way and that, looking for any other problems. None. It seemed unwarranted to just scrap it.
I removed the stud and found that the threads were, indeed, stripped.
I looked through my spare studs until I found one that was over-sized on one end but had the same 8mm x 1.25 threads on the other end. I called a VW specialist. He suggested that instead of drilling and tapping the hole to accommodate the over-sized stud, that I use a Helicoil. This would allow use of the original stud. Since I have a Helicoil kit of the correct size, I decided that I should do that.
Illustration 3 shows the over-sized stud, the correct 8mm stud and the stud which I removed from the carburetor, still holding what’s left of the threads.
What I did not have was a 21/64th drill bit. In order to prepare the stud hole for taping to the outside diameter of the Helicoil, I needed this special sized drill bit. I went around the corner and bought one for $6.00.
Once the stud hole was drilled to size, I used the tap which came in the Helicoil kit to thread the reamed hole.
Next, I selected a coil and screwed it onto the end of the installing tool (also part of the kit). I could feel the Helicoil “seating” itself as it screwed into the fresh threads. The coil was stretching ever so slightly so that by the time I had installed it, it was tightly secured in the new threads. I backed the installing tool out of the threads. Using a small pair of pliers, I broke off the installing tang at the top end of the Helicoil.
I selected a good stud and double-nutted it. I screwed it into the Helicoil and we were done, except for removing the double-nuts.
It was well worth the little time, money and effort that it took to save yet another vintage carburetor from the recycle bucket!
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Another useful article from Jay. Very informative and certainly worth to keep in our file for reference.
Keep up the good work Jay.
Hello, Larry…my friend in Ho Chi Minh City! It is always good to hear from you. Yes…you know me–always wanting to salvage any VW part which I can–and especially any 1967 Beetle part. My greetings to your wife and to your Volkswagen associates there. jay
Great work, once again, Jay!
Thanks, Eric, for making all of this possible for us ’67 Bugologists! jay
Another quality article Jay, really good read.
It’s been so long since I worked on VWs, it was a bit jarring to realize the carb carries the studs, rather than the manifold ala P-356. So you need to drill two holes in your workbench to set the carb down flat? Yikes!
Hello, Brian…Thanks for commenting. Well, yes, this little “cousin” to the P-356 DOES indeed have the studs threaded into the carb rather than into the manifold flange. I’ve not bolted any carb to my workbench but it stands to reason for ease of handling. jay
It’s easy. Old fuel line over the studs, and then into your small vise. No thread damage, and as secure as being on the manifold.
Or, as in some carbs iv continually worked with a plate of metal, 1/4 thick ,by 2″ wide, and 6″ long. Drilled for studs,and slotted stud holes with dye grinder for different bolt spread sizes. And a hole saw for carb boar size, largest. Bolt carb to it through entire proses of cleaning, and rebuilding. Clamps to bench, vise, or hand held, or stands on its own.
Richard…these are GREAT ideas! Manys the time when I should have followed your good advice! jay