What is this Passage in the Vacuum Chamber of the CV Carbs?

[Guest]

And does it lead to anything/anywhere? I finally got a replacement set to replace my broken #3 carb for the 79 GS550 that I picked up. Terribly filthy, but they were destined for my carb dip regardless. Using the guide shown on Cliff's and it says after dipping to shoot carb cleaner into this hole.

DSC07962.jpg

Thing is, that even thought the casting below it suggests it leads somewhere, I can't get carb cleaner to blow out the other end (wherever that is). I've also tried compressed air to no avail. Even though this is the 2nd set I am cleaning in my life (first was for a 650 with CV carbs) I can't remember for the life of me if this hole has an outlet somewhere and I don't want to assume something that isn't correct.

Thanks in advance...

Geoff

[londonboards]

I believe it's stopped off down inside the hole.

It was drilled out to create the passage for the pilot fuel feed to the top half of the carb and ends up providing the fuel which is metered by the screw needle pin on the top.

Look at the passageway sideways on and you will see where it then goes into the boy of the carb at the top. They drilled a hole in the side too (it goes upwards and forwards) but they plugged this one with a little blob of what looks like brass. There are several other places around the carb body where you can see these little brass plugs. They just didn't bother with plugging the one you refer to at the top like the others.

[Steve]

No need to try to open that passage. You can sort of follow the casting to see where fuel flows, and you can also see where they have drilled holes in the casting, then plugged them to keep the fuel INSIDE the carb. That is one of those plugs.

.

[UKPR1]

London and Steve - Thank you both!