If anyone has better or more accurate information on this it would be appreciated Some pictures from a google search so not sure of accuracy.

There is also an effect caused by the diameter of the emulsion tubes but I am not certain how this effects the engine running If there are more holes at the top then the air fuel ratio will be weak at low rpms.Īs the rpms rise the fuel level around the emulsion tubes drops exposing holes gradually farther down the emulsion tube so the lower the holes are around the emulsion tube the weaker the mixture will be at high rpms. The holes at the top of the emulsion tubes are exposed to air so these effect the low rpm enritchment. When idling the fuel level around the emulsion tubes is the same as that in the float chamber which is why it is so important to set the float level. I am no expert on Weber carbs but my understanding of the emulsion tubes is as follows: New crappy image uploader is actiing up again. I will be tuning with a wideband AFR but just want to know what effect the different emulsion tubes will have, where hey will add or remove fuel in the rpm range as compared to another tube, initially I am using F7's as they were recommended to me, I usually use F11's but the chokes with this setup may require different E tubes than usual The larger the emulsion tube diameter the less fuel can flow to the auxiliary venturi so that would mean the larger the E tube diameter the leaner the mixture at high rpm, is that how it works? I know the fuel is sucked in the main jet at the bottom and up through the holes at the bottom of the tube then fuel flows along the outside of the tube upwards, the holes in the middle and top of the E tubes are where air mixes with the fuel at low-mid to high revs, low rpm being the top of the emulsion tube and the holes in the middle would be for higher rpm, is that correct? When comparing emulsion tube hole placement and diameter of the tubes how does this effect the fuel delivery?

The random numbering of weber emulsion tubes is a little confusing to say the least I will be tuning a 2 litre pinto tarmac rally engine soon with twin 50 webers which have a unique set of high velocity chokes, I have a number of different emulsion tubes, F7, F11, F16 and one or two more, can someone tell me what the differences will be on the fuel map vs rpm?Īs I understand it F16 will be rich in the low rpm range, F7 also rich at low rpm but a little less than F16 and the F11's have a more even spread, is this correct?

Weber f7 emulsion tubes