Carburetors (& air filtration)

While dual carbs will undoubtedly give greater performance, I have chosen to stick with the stock 34 PICT 3. My reason is we are operating between 2,790 and 8,000 ft in elevation. We have learned to modify the 34pict3 so we can actually get some mild performance and still use a good air filter system.  The original MANN air cleaners look good for an original restoration but is lacking for actual use. Think about it, the originals are at least 40 years old and are worn out. Also, they are an oil bath air cleaner, which require much more cleaning.  I have gone to the set up pictured here.IMG_4920


This next pic shows the case breather system:


The next pic (insert pic #IMG_4919) shows them both together.


We use the K&N washable filter for both. I haven’t seen anything yet that does a better job. The dual set- ups run too rich and have a tendency to wash the cylinder walls with raw fuel at the higher altitudes; they are hard to adjust because the adjuster for the left carburetor on some applications is tight to the dog house. If you’ve gotta have duals, one of the better applications has been the dual Kadrons.  It’s the only one I would consider because of my demand for reliability.

Back to the stock carbs…

  • I modify the Solex by changing out the 127.5 main jet to a 130 with a stock cam, and a 135 with an Engel 110.
  • The air correction jet is bumped from 75z to 80z .
  • The pilot jet goes from the usual 55g to 65g.
  • The accelerator pump injector is drilled out to .0050 and then installed in the carburetor to be squirting right on the throttle plate crack as it first opens. This also helps with the hesitation when using a 009 distributor with the Solex.
  • The super small jet under the cap screw under the pilot jet is changed from 42.5 to 47.5.  This has been the best I have found for keeping the Solex and getting some measurable performance gains without overheating .

There is a new carb out now called the Pierburg 34pict3.  They are made from the original German molds and are supposed to be great.  These are being made in Malaysia.  I got one a year back when they first came out and they were horrible.  The vacuum on the left side was blowing air rather than having a vacuum to run a stock distributor.  They had a bunch of these returned to the point of sale and they got a bad rep.  This problem seems to have been corrected.  I bought one from CIP1 last month and put it on my Thing just as it came out of the box.  After dialing it in, it ran very well and with the dwell set at the low end of 44-50, the hesitation was not noticeable. I plan on trying another and modifying it for my needs.  For me, I prefer to do a good rebuild on a stock German 34 PICT 3…….then do my mods from that point.

Warning—use screw type clamps on all fuel line connections. They are cheap and fires are not. It’s just that simple!!!

Also check your fuel line where it attaches to the brass stem that goes into the top of the carburetor. These have been known to come out of the carburetor. If loose, you can coat the stem with JB Weld after scoring the stem. Larry Green had his nice 1835 engine catch fire on his way to work a few years ago because of this. It was at 4:30 AM and when he called the Boise police they asked what color his car was so they could give a description to the responding officers. Larry replied it was the ONLY VW on fire in the middle of the intersection!

– Mike Humeston