staticattic

Just out of curiosity, what differences can be seen when going from dual 44's to a single 44? I am so tired of having to dink with my carbs every week or so. Do all duals require weekly maintenance to keep them in sync? I know nothing on any type of engine is "set it and forget it", but having to dink with something every week is getting old. I thought it was just me, but I get the same results when I pay the local VW shop to adjust them and check out the engine. What do you guys think? Are they just taking my money and not really doing anything? Is there something else beside plugs, carbs, and timing I need to be looking at? It always seems cylinders 3 and 4 are the ones that get out of sync. When I say "out of sync", I mean the snail gauge on those will be 2 or once even 3 digits different from cylinders 1 and 2.   

Jeff
72 Super Beetle
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YELLRHD
Static,
I'm begining to think you may have a bad carb on the 3/4 side.
Most dual carbs once set should only need an occasional check during your oil change valve adjustment.

Are these real webers? or the currently available chinese made ones?

I have had both the dual 44s and dual Solex singles and have never experienced that kind of fluctuation.

What kind of linkage are you running? The CB hex bar is a good one better than the stamped steel set ups.

Also the Gene Berg ones are very good but expensive.

I'm sure Ryan or one of the other guru's will chime in.
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staticattic
I have been doing a bit of research and here is what I have found so far:
  1. Going to a single carb is not as simple as just unbolting the dual setup and bolting a single carb on.
  2. Dual throat IDF carbs were not really designed as a single operation carb.
  3. A single carb can't flow as much air. Airflow, CFM, equals horsepower.
  4. Length of the manifold contributes to fuel falling out of suspension
  5. The combination of VW manifold end pieces, center section manifold, and a dual throat carb create a whirlwind of reversion and back flow.
  6. The back flow causes a constant rich condition for numbers 1 and 3.
  7. All of the jetting has to be re-configured. From what I have found, a single 44 on a 1776 will need to start out with: 34mm venturi, 1.60 main gas, 1.75 main A/C, F11 emulsion tube, .60 idles, and .80 P/Jet.
On the positive side, a single IDF carb has 50% less maintenance and keeps the carb away from sand or mud slinging tires if running a baja.

Something I have learned while researching this, jetting is always based on venturi size. One thing I have never checked or changed are the venturi size that I am running. The higher the RPM, the bigger the venturi needs to be. The trade off though is low end will suffer due to low air flow through the carbs. I am wondering, since jetting is based on venturi, if my venturi are too large (or small), then changing the jetting will not really have much effect. For dual 44 IDF on a 1776, Weber suggests starting with these values: 36mm venturi, 1.50 main gas, 2.00 main A/C, F11 emulsion, .60 idles, and .50 P/Jet.

Jeff
72 Super Beetle
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68autobug
WOW
 
I 'm glad I only have a single carburetor....  loi
 
I do have dual Kadrons I was going to fit but My car goes OK
 
very pleased with its performance
 
Lee
 

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