Seeking Truth on Emulsion Tube Positions

[larrydreed]

Thanks to XS11.com for the Birthday greetings. I turned 66 today!
I have the carbs down for cleaning on a 79 SF. I realize the two inside cylinders utilize a richer mixture to maintain slightly cooler operating temp. My problem is the nozzle or emulsion tube placement. One set of nozzles has 16 small holes and the other has only 10. I've searched the formus and find conflicting answers. So once again, the question is which emulsion tube would create the richer mix, the one with 16 side holes or the one with 10 side holes? Also, what is the theory on how these holes affect the mixture? Do the holes prevent a lesser amount of fuel to be pulled into the air flow, or do they cause a greater amount of fuel to enter the air flow?
Curious in Monterey, TN
Larry

[petejw]

happy 66th!
the holes in the emulsion tubes allow for air,
the more holes the leaner the mixture, put the
richer tubes in the center carbs.

[egsols]

Larry,

Like petejw said put the tubes with 16 holes in 1 and 4, these tubes should have a 266 marked on them. The other ones, should be marked 301, go in numbers 2 and 3.

[larrydreed]

Thanks Pete and Ernie,
I am curious as to how more air can enter via these holes when the tube is immersed in the float bowl filled with gasoline. What is the science?
Larry/Monterey, TN

[oseaghdha]

It sucks gas through the middle from the end.
There is an air bleed into the well.
More holes = more air in the mix.

This is the case for both the main and idle tube.

Next time they are apart, check it with your carb spray.

[TopCatGr58]

Here's the TECH!

Hey Larry,

Here's a diagram that shows the flow of air/fuel thru the carbs/jets, etc.!
T.C.

[larrydreed]

Ok. I'm convinced! Thanks for the diagram TC. Once again the info from this site is superb.
Larry/Monterey, TN

[Vanman]

Well i never noticed the differences between the emulsion tubes. Good thing is, I have always kept the parts for each carb together and separate from the other carbs. But I would be interested to know if there are any other parts that are different between the carbs. I have an '82 XJ

[bikerphil]

I would be interested to know if there are any other parts that are different between the carbs. I have an '82 XJ

Pretty sure (99%), that just the emulsion tubes and the main jets. As long as you keep 1-4 and 2-3 the same, you should be good. Or make all 4 the same. The idea of 2-3 being different than 1-4 was eventually scrapped.

[Vanman]

Thanks! I am pretty sure that my mains are all the same so probably the emulsion tubes are also. But it's winter and I'll probably take them apart to make sure, now that my curiosity has been peaked.