Is there a fitting missing?

[patd]

When I was cleaning the carb a couple of days ago I noticed that this hole looks like it is missing a fitting, I think that it might be a vent for the fuel bowl, It has treads inside, When I squirt carb cleaner down it the fuel in the bowl gets agitated, In the picture it is at the 4 O'clock position on the outside of the carb, you can see it has a little hole inside. anybody have any ideas? :confused:

 

 

[drxfter]

Not 100% sure, but I looked up a schematic in my "Autobooks" workshop manual and its identified as a 'secondary slow jet'. It looks like its passage goes into the bottom of the 'secondary emulsion tube' cavity. What it does exactly I'm not sure. I understand EFI better than carburettors these days! :)

[nis720]

On my old Z24 carb it had a tube attached in there and vented into the charcoal canister. I think it's like an overflow for the fuel.

[patd]

Thanks guys, I am thinking that it is a vent too. The truck runs fine with no fuel leaks or anything so I guess that it will not hurt anything to leave it like it is. :hmm:

[alex843]

Its been a while since I took my stock carb off. But isnt that the vacuum advance for the distrubor?

[patd]

The vacuum advance on this carb is on the left hand side, you can see the small skinny line just on the left hand side of the accelerator pump linkage.

[alex843]

Thats right its on the bottom of the carb. I still have my stock carb, Ill take a look at it when I get home.

[datzenmike]

Not 100% sure, but I looked up a schematic in my "Autobooks" workshop manual and its identified as a 'secondary slow jet'. It looks like its passage goes into the bottom of the 'secondary emulsion tube' cavity. What it does exactly I'm not sure. I understand EFI better than carburettors these days! :)

 

 

That's what it is! You can see the jet in the hole. This is supposed to be capped off. The secondary slow jet has to do with proper fuel supply when transitioning from the primary to the secondary system.

 

I would keep an eye out for an old carb and replace the missing one.

[patd]

Well that takes care of that.. I guess finding the correct cap for it will be like winning the lottery, zero, zilch, I wonder what I can use to cap it off? plain cap or does it have some jet in the cap? Thanks for letting me know drxfter, I knew that you guys would know what went in there. Do you think that it affects the fuel mileage?

[datzenmike]

No idea on the mileage. There are lots of guys with old carbs, scrap carbs, carbs in pieces, spare parts. No Datsun owner doesn't have their own personal wrecking yard of scrapped carbs. Ask around or keep an eye open when in a real wrecking yard... should fit in your pocket. :D

 

 

The 720 carbs Z20/22/24 all have them too.

[patd]

No idea on the mileage. There are lots of guys with old carbs, scrap carbs, carbs in pieces, spare parts. No Datsun owner doesn't have their own personal wrecking yard of scrapped carbs. Ask around or keep an eye open when in a real wrecking yard... should fit in your pocket. :D

 

 

The 720 carbs Z20/22/24 all have them too.

 

Thanks Datzenmike, I will keep an eye on ebay, and check some of the junk yards, (that will give me something to do) :thumbup:

[Str8_69]

Thanks Datzenmike, I will keep an eye on ebay, and check some of the junk yards, (that will give me something to do) :thumbup:

 

Hit a good hardware store and find a small rubber plug you can fashion as a temporary fix until you find a fitting for it.

 

Just my .02, Done it many times and a couple of them are permanent.

[hang_510]

No Datsun owner doesn't have their own personal wrecking yard of scrapped carbs.

:lol:

i only have 1 scrap DCOE :w00t:

no others left!!! :)