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A neighbor has just purchased a tired 74 Thing. He ordered a replacement engine which we installed with all the original old tin, distributer, carb (an old 30/31 Pict with adapter), fan and gen. We did a complete tune up on it including valve adjustment, timing to book spec, etc... We got the little bugger running great. He ordered a rebuilt Pict carb for his 74. We put it on. It fit great, checked the adjustments etc. All looked good. We started it up and it ran like atop for about 10 seconds when suddenly fuel just spit it self out of the brass tube at the top of the carb, like a giant flame capable lugi launcher! The engine promptly stalled from flooding.

We checked fuel pressure - 2.5lbs all ok. We wiped up the launched fuel, let the engine breath out the flooding for 20 minutes and tried again. This time just a few seconds of running great, then the mother spit gas like a redneck at a tobacco spitting contest, flooded and stalled.

Ok... what causes this!? Can we fix it? We put the old carb on and the engine runs perfect again. Thanks for your help!

Where did you buy this death star of a carb. I would retrun it to from where it came or at least throw it away. Is this a Brosol or Pierburg carb? I have not heard of this but based on your actions it would have to be the carb. What a scarey ordeal... I do not like a gas fire... outside the engine. Been there done that.. K-mann

Bad float(full of fuel),reversed float hold down (plastic crescent shape piece), contamination in the needle seat assembly are some possibilities.

If the carb is a replacement (such as a "Brosol"), toss it! I had one of these fresh out of the box (brand new) installed on my Thing. It would start hard, and took awhile to warm up, and would never hold a great idle. After countless checks and re-checks for proper adjustment, I went and found an ORIGINAL German 34 pic 3, and rebuilt it. I disassembled it, soaked all the parts overnight in carb cleaner, then reassembled it. I set the volume control screw at 2 and 1/2 turns out, the bypass screw (large) at 1 and 1/2 turns out (to get close to a 850 RPM idle). I pre filled the fuel bowl with gas, installed the carb and pressed the gas pedal ONCE. With the starter spinning only about 3/4ths of a turn, the engine fired and ran like it was brand new! I only had to adjust the Bypass screw a bit to idle the engine down.

From now on, no more BROSOL parts for me. If I cannot find original german parts that are rebuildable, I'll continue to look!

Speak the truth Brutha Bucko. I have no use for that aftermarket trash either.. In some parts of the country it is nearly impossible to find the orginal stuff any more. The secret is to look until you find the good stuff. It is worth every penny you have to pay for it. I recently sold an original Thing 34 pict 3 that came off of my running Thing to a pal for a fair price. He was thrilled that he finally got his Thing running after 6 months of struggling with unit after unit of Brosol trash. I have heard that some folks have had good luck with the China version 34 pict 3 but if I needed an original carb it would be a Solex original or nothing.... Although I do love my Delortos and Zenith carbs as a power upgrade...

K-mann

To add to this thread, I just experienced yet another problem with my carb. After rebuilding a German 34 pic-3, I found an intermittant fault where the engine would surge, but not all the time. I posted a question on the Samba asking about water in the tank causing this. I pulled the carb, and checked all my work yet again. What I discovered was that there was enough play in the bottom shaft to allow accessive air through it, messing up the critical adjustments of this carb. It should be well known that these carbs are very touchy, and that the throttle and bypass screw adjustment are very important to get this carb to work properly. Having this small air leak was messing up the carb's idle. I took it in to have new bushings installed (brass), and the problem is solved.

I am in total accord with the use of Solex pic 3 carbs on a stock set up.
I would suggest anyone needing to service their carb, especially replacing the bushings, to contact Richard Carey in Madison, WI.
He runs ads regularly at Samba. He gave me free advice before sending him a carb and it worked great! A gentlemanly gesture, and something he didn't have to do. But he did.
He addresses the bushing problem in his Samba ad:

"We believe that the German made Solex is a much better choice than what is available today from Mexico and Brazil. The problem with the old German carbs is that over the years the throttle shaft wears out the soft aluminum bushings allowing air to leak through, essentially making the carb useless. We have cured this problem, and improved on the original design, by milling out the old aluminum bushings and inserting much better wearing brass bushings. This restores the bushings to original specs, and the brass bushing will ensure that the shaft does not wear the bushings for a much, much longer time than the original bushings."

Check it out:
http://www.thesamba.com/vw/classifieds/ ... p?id=64882

Great info; I wish I had seen that about three weeks ago, then I would not have gone through the aggravation I had diagnosing the carb's faults!!!

Steve::: Great post and great resource. At certain times of the year I have access to a huge supply of original VW carbs that are in various states of disrepair. The rebushing issue is major. I am into old Italian Dellorto and Old Porsche NDIX Zenith and both at times are salvagable if and only if the throttle shaft bushing can have the same treatment you mentioned.

Thanks for the help gang! I found that the "rebuilt" carb had an assembly problem. Some Ass had embled it wrong. That funny "U" shaped plastic thing that holds the brass pivot for the float bowl was in back-ass-wards. I flipped it around and that fixed our problem. Thanks!
tooter

I've noted the manuals do not picture the placement of that plastic thing very well. How about telling all us other Asses which is right and which is wrong?