Weber Jetting Survey

[Caprimaniac]

Just a quick update on the troubles above.

What I found after some checking was: Left side plugs: all 4 dark brow/ black on the RHS all 4 plugs were light brown/ white-ish. I have a fuel regulator splitting L/R in AN6 lines at the rear of the carbs. Could this be due to sideloads (g-forces)? Is it possible???

[Gaz64]

Rune,

Run the smallest needle and seat that still gives maximum power.

You can get 1.75mm up to 2.5mm in 1/4mm steps.

If you are on an oval and only turning right, it may explain your richness on the left bank.

You may need to machine up some spacers to emulate a canted intake manifold, with the carbs leaning towards each other.

The main well and the discharge nozzle are line with the centre of the float bowl volume, and it would be difficult to overcome your problem any other way.

The float hinges from one side and will have more closing force on the valve with the fuel stacking up on the other side of the carb, thus giving a lower "fuel level" at the nozzle. The reverse is true for the other bank, thus one bank rich, one bank lean.

[Caprimaniac]

Very good advices, GAZ. Maybe I can set the floats on the LH side somewhat lower to overcome the problem. Tllting is possible, but alot of work...

Since my fuel- lines are figured as a T (ending at the front of each carb bank) I think that if the problem lie in the lines and the amount of fuel in the two banks, a connection at the front might do some good as well.

I looked at the Redline Weber webshop and I found the largest needle & jet for the 48 IDF available was the 200... (Although in my not- updated catalogue they are listed up to 250, as you mention, GAZ.)

Here we have a picture showing the plugs (4LH/ 4 RH). Quite consistent, or what?